1 Volume 24 2025 e255791 Original Research Braz J Oral Sci. 2025;24:e255791http://dx.doi.org/10.20396/bjos.v24i00.8675791 1 Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil. Corresponding author: Noéli Boscato Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas Gonçalves Chaves 457, room 508, Pelotas, Brazil. Email: noeliboscato@gmail.com, noeli.boscato@ufpel.edu.br Editor: Dr. Altair A. Del Bel Cury Received: February 2, 2024 Accepted: December 12, 2024 Influences of light temperature and room wall colors on tooth shade matching: a spectrophotometric analysis Eduardo Trota Chaves1 , Camila Raubach Dias1 , Fabiola Jardim Barbon1 , João Pedro do Couto Caetano1 , Noéli Boscato1* Aim: This in vitro study investigates how light temperature and room wall colors influence color differences in two commonly used tooth shade guide scales for color selection in dentistry. Methods: We examined the effects of three light temperatures (warm light at 3000K, neutral light at 4000K, cool light at 6500K), four room wall colors (white, blue, red, black), chromatic shade values (low, medium, high), and two shade-guide scales (Vita Classical and Biotone). Color differences were measured using an EasyShade spectrophotometer, with ΔE00 calculated via the CIEDE2000 method to assess perceptibility and acceptability thresholds. Results: The study revealed that high chromatic shade values on both scales showed a greenish shift in the a* coordinate, while medium and low values inclined towards redness. All b* values exhibited a tendency towards yellowness. For the Vita Classical scale, neutral light conditions did not significantly affect ΔE00 across any room wall colors (p > 0.05). However, for the Biotone scale, high chromatic values under specific light conditions significantly surpassed the clinical perceptibility threshold in white versus red room simulations (p < 0.05), indicating a notable impact on color perception. Conclusions: Our findings suggest that both light temperature and room wall color significantly affect tooth shade perception. Adjustments in environmental conditions can corroborate for more accurate color matching between natural tooth and dental restorations. Special attention must be given to extreme light temperatures and contrasting wall colors. These results support the importance of standardized environmental settings in dental practices to ensure reliable esthetic outcomes. Keywords: Spectrophotometry. Temperature. Color perception. Tooth. Colorimetry. https://orcid.org/0000-0002-5313-4980 https://orcid.org/0009-0005-1010-6671 https://orcid.org/0000-0001-5572-432X https://orcid.org/0000-0002-2595-9475 https://orcid.org/0000-0002-3817-1732 2 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Introduction Color perception in dentistry poses a professional challenge due to the subjective nature of human visual assessment, which involves the interaction between the dental element (object) and light incidence1,2. Restorative materials such as composite res- ins and ceramics are widely used due to their optical properties, which closely mimic those of natural dental structures. However, accurate selection of material color is crucial for meeting patient aesthetic expectations effectively1,2. Tooth shade selection is a critical aspect of aesthetic restorative treatments, as an improper match between the restoration and adjacent natural teeth plays an important role in the treatment results2. Various factors must be considered to achieve an excellent shade match between artificial and natural teeth, regardless of the technique or dental material employed. An ideal shade match is achieved through the perfect alignment of the tooth and restoration colors, influenced by luting and adhesive materials, and modified by different lighting conditions and environments3. Various tools have been developed to aid this process, including visual shade-guide scales, spectrophotometers, colorimeters, and digital photography2. The use of tech- nological or digital devices offers greater reliability and precision, as they minimize external interference. Nonetheless, their use in clinical practice remains limited. Consequently, visual shade-guides remain the predominant method for tooth shade determination in dentistry, despite their reliance on subjective visual comparison4,5. Different lighting conditions and room wall colors can promote perceptible changes in color perception, leading to unsatisfactory aesthetic outcomes due to the phenom- enon known as metamerism4-6. Factors such as visual fatigue, contrast effects, and optical metamerism can also affect tooth shade selection. Previous studies have recommended that the work envi- ronment feature neutral wall colors, with natural light deemed the most suitable for tooth shade determination5,6. Investigations have highlighted the complexities of the tooth shade matching process, showing a significant role of illumination in the accu- racy of color selection4-10. Al-Dwairi et al.11 (2014) observed notable gender differences and moderate agreement between skin color and tooth shade under various light- ing conditions. Computational optimization methods have proven more effective in extending color coverage for dental shade guides12. The VITA Linearguide 3D-Master has been shown to offer superior color matching due to its enhanced distribution of tooth color shades5. Additionally, controlled lighting conditions have been shown to improve the reli- ability and consistency of visual shade matching, emphasizing the importance of standardized illumination in achieving accurate tooth shade selection13. The pri- mary objective of this study is to investigate the effects of light temperature (i.e., warm, neutral, or cool) and room wall color (i.e., white, black, blue, or red) on color differences (ΔE00) using two shade-guide scales (i.e., Vita Classical or Biotone) available for tooth shade selection in dentistry. The hypotheses tested are that dif- ferent light temperatures and room wall colors would significantly influence color 3 Chaves et al. Braz J Oral Sci. 2025;24:e255791 differences in tooth shade selection across the two shade-guide scales tested, and that high, medium, and low chromatic shade values would yield distinct ΔE00 values under different exposure conditions.” Materials & Methods Study Design This in vitro study employed a 3×4×3×2 factorial design considering: light temperature (three levels: warm light at 3000K, neutral light at 4000K, and cool light at 6500K); room wall color (four levels: white, blue, red, and black); chromatic shade value (three levels: low, medium, and high); and shade-guide scales (two levels: Vita Classical from Vita Zahnfabrik, Bad Säckingen, Germany, and Biotone from Dentsply Sirona, Kon- stanz, Germany). The response variables were color differences (ΔE00) and CIE Lab* color coordinates. Sample Size Estimation and Power Analysis Our sample size estimation and power analysis were informed by the study by Gomez-Polo et al.14 (2014), which used the Easyshade compact spectrophotome- ter to assess agreement between visual and instrumental color matching methods. Following their approach of three repeated measurements, we extended our proto- col to five measurements per factor combination to enhance data reliability and pre- cision. We conducted our power analysis aiming to detect a medium effect size (f = 0.25), with an alpha level (α) of 0.05 and a power (1 - β) of 0.80. These parameters were chosen to ensure that our study was adequately powered to detect clinically meaningful differences in ΔE00 values under various lighting and environmental con- ditions. All measurements were performed by the same experienced operator in a light-controlled environment to maintain consistency and minimize external variabil- ity, reinforcing the validity of our results. Light Temperature and Room Wall Color The average daylight temperature is 6500K10,15, equivalent to the cool light temperature used in this study. From the light temperature scale, three wavelengths were selected: warm at 3000K, neutral at 4000K, and cool at 6500K. These were reproduced using LED lights from Luminatti (São Paulo, SP, Brazil) with an efficiency of 85 lm/W and a 30W bulb generating approximately 2550 lumens. Four room wall colors (red, blue, white, and black) were selected to simulate the clinical and laboratory environment within a photographic studio box. Shade-Guide Scales For this study, we selected the Vita Classical and Biotone shade-guide scales, which are widely recognized and utilized in dental practices globally, based on their prevalent use in clinical settings. These shade guides are not only popular but also represent different materials and color palettes, which is crucial for understanding how vari- ous environmental conditions affect the perception of different dental materials. Vita Classical is predominantly used with composite resins and ceramics, making it ideal 4 Chaves et al. Braz J Oral Sci. 2025;24:e255791 for studies involving these materials. In contrast, Biotone is frequently employed with acrylic-based materials, providing a comparative basis to evaluate and assess the influence of light and environmental factors across a broader range of dental restor- ative materials. The Vita Classical shade-guide includes 16 chromatic shades, from which three chromatic shade values were selected: high (B1), medium (A3), and low (C4). The Biotone shade-guide consists of eight chromatic shades, selecting high (66), medium (61), and low (81) chromatic shade values (Figure 1). Figure 1. Vita Classical (Vita Zahnfabrik) (a) and Biotone (Dentisply) (b) scales arranged by value order, showing selected color guides in red. Color Measurements and Calibration with Luxmeter A Puluz photography lightbox (Shenzhen, China) measuring 20×24×22 cm was used for ΔE00 measurements. Lights with three different temperatures were attached to the top of the box. Light intensity was standardized and verified using a digital lux meter from Intrusul (Esteio, RS, Brazil) to 445 lumens/m² after each color measurement (Figure 2). Figure 2. Location of assessments with a lux meter in the center for standardization of luminosity (a); color guide positioned in the center of the simulated environment (b). 5 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Color Differences (ΔE00) and CIELab* Coordinates ΔE00 measurements were conducted with each chromatic shade centrally positioned in the study box. Five measurements were performed at each light temperature and room wall color for high, medium, and low chromatic values of each shade selection scale using an Easyshade spectrophotometer (Vita Zahnfabrik, Bad Säckingen, Ger- many) based on the CIEDE2000 system. The probe tip was positioned on the middle third of the coronal labial surface of each artificial tooth. Color differences were calcu- lated using the CIEDE2000 formula: ∆E00 = + + 2∆L’ kL SL 2∆C’ kC SC ∆C’ kC SC 2∆H’ kH SH ∆H’ kH SH + RT 2 1 Where ΔL’, ΔC’, and ΔH’ are the differences in lightness, chroma, and hue between two sets of color coordinates; RT is the rotation function accounting for the interac- tion between chroma and hue differences in the blue region; and SL, SC, and SH are weighting functions adjusting the total color difference for variation in perceived mag- nitude with location of the color coordinate differences between two color readings. The terms kL, kC, and kH are correction factors for the experimental conditions. This study set the color difference perceptibility and acceptability thresholds at ΔE00 = 0.8 and ΔE00 = 1.8, respectively12. CIELab* coordinates were noted and considered in separate analyses. Statistical Analysis ΔE00 means and standard deviations were presented through descriptive analysis. The ΔE00 between-group differences related to high, medium, and low chromatic val- ues, considering the Biotone and Vita Classical shade-guides, were analyzed using two-way ANOVA, considering light temperature vs. room wall color, followed by post-hoc Tukey test comparisons (α= 0.05). Data normality was analyzed using the Shapiro-Wilk test, and non-parametric data were transformed into ranks. CIELab* coordinates were also analyzed using two-way ANOVA, considering chro- matic shade values vs. light temperature, followed by post-hoc Duncan’s test comparisons (α = 0.05). Results Table 1 presents the mean values of ΔE00 across high, medium, and low chromatic shade values for both Vita Classical and Biotone scales, considering variations in light temperature. All ΔE00 values fell below the clinical acceptability threshold (ΔE00 = 1.8). For the Vita Classical scale, the medium chromatic shade value (shade A3) in the Warm vs. Cool light temperature condition exhibited a statistically significant difference (p = 0.001) compared to the Neutral-Warm and Neutral-Cool conditions. Chromatic shade values, specifically shade B1 and medium (shade A3), registered values exceeding the clinical perceptibility threshold (ΔE00 > 0.8). There were statistically significant differences (p ≤ 0.002) observed for the high chromatic 6 Chaves et al. Braz J Oral Sci. 2025;24:e255791 B1 shade when compared to A3 and C4 shades under the Warm vs. Cool light tem- perature condition. Table 1. ΔE00 mean and standard deviations values for high, medium, and low chromatic shade values considering Vita Classical and Biotone scales at different light temperatures and tooth shades. Scales Tooth-shades Neutral × Warm Neutral × Cool Warm × Cool Vita B1 0.54 (0.39) Aab 0.66 (0.51) Aa 0.98 (0.53) Aa A3 0.75 (0.20) Aa 0.81 (0.20) Aa 0.27 (0.13) Bb C4 0.26 (0.03) Ab 0.28 (0.03) Aa 0.26 (0.08) Ab Biotone 61 0.81 (0.32) Aa 0.70 (0.19) Aa 0.44 (0.10) Aab 66 0.26 (0.11) Bb 0.50 (0.35) ABb 0.65 (0.35) Aa 81 0.51 (0.43) Ab 0.43 (0.12) Ab 0.40 (0.35) Ab Different uppercase in the same rows indicate significant between-group differences considering the light temperature (i.e., Neutral × Warm; Neutral × Cool; Warm × Cool) (p < 0.05); Different lowercase in the same columns indicates within-group differences considering the chromatic shade values for each shade selection scale (i.e., Vita Classical and Biotone) (p < 0.05). For the Biotone shade-guide scale, only the medium chromatic 66 shade value dis- played statistically significant differences (p = 0.004) according to light temperature variability. The Neutral vs. Cool light temperature condition was found to be similar to the other conditions (Neutral vs. Warm and Warm vs. Cool; p ≥ 0.098), which showed significant differences from each other (p = 0.004). The Neutral vs. Warm light tem- perature condition did not significantly alter the high-chromatic 61 shade value, which was the only value to exceed the ΔE00 perceptibility threshold (>0.8). Table 2 details ΔE00 mean values for the Vita Classical scale across cool, neutral, and warm light temperatures under different simulated room wall colors (White vs. Black, White vs. Red, and White vs. Blue). All ΔE00 values remained below the clini- cal perceptibility limit (ΔE00 ≤ 0.8). However, the simulated room wall colors did not produce a statistically significant difference for the high chromatic B1 shade value (p = 0.944). In contrast, ΔE00 means for medium (A3 shade) and low (C4 shade) chromatic values were significantly different, particularly under cool light tem- perature in the simulated White vs. Black room wall color condition compared to White vs. Red and White vs. Blue (p ≤ 0.001). The White vs. Black condition yielded the lowest ΔE00 mean values, whereas White vs. Blue comparisons revealed a sig- nificant difference only for the low-chromatic C4 shade value under warm light temperature (p ≤ 0.03). 7 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Table 2. ∆E00 mean and standard deviation values for high, medium, and low chromatic shade values considering the Vita Classical scale at different room wall color comparisons, light temperature, and tooth shades. Light Temperature White × Black White X Red White X Blue High Value (B1) Cool light 0.71 (0.54) Aa 0.58 (0.48) Aa 0.63 (0.44) Aa Neutral light 0.35 (0.11) Aa 0.25 (0.05) Aa 0.31 (0.35) Aa Warm light 0.68 (0.30) Aa 0.60 (0.54) Aa 0.47 (0.32) Aa Medium Value (A3) Cool light 0.15 (0.10) Bb 0.49 (0.20) Aa 0.57 (0.15) Aa Neutral light 0.59 (0.16) Aa 0.68 (0.25) Aa 0.56 (0.15) Aa Warm light 0.38 (0.24) Aab 0.16 (0.02) Ab 0.31 (0.19) Aa Low Value (C4) Cool light 0.11 (0.02) Bb 0.44 (0.18) Aa 0.58 (0.32) Aa Neutral light 0.33 (0.23) Aa 0.27 (0.10) Aa 0.27 (0.05) Aa Warm light 0.28 (0.09) Aa 0.25 (0.14) ABa 0.14 (0.06) Bb Different uppercase in the same rows indicate significant between-group differences considering the light temperature (i.e., Neutral vs. Warm; Neutral vs. Cool; Warm vs. Cool) (p < 0.05); Different lowercase in the same columns indicates within-group differences considering the chromatic shade values for Vita Classical scale (p < 0.05). Table 3 presents ΔE00 mean values for the Biotone scale across cool, neutral, and warm light temperatures under varying simulated room wall color conditions (White vs. Black, White vs. Red, and White vs. Blue). All values were within the clin- ical acceptability limit (ΔE00 ≤ 1.8). The high chromatic 61 shade value exceeded the clinical perceptibility threshold (ΔE00 ≤ 0.8) under neutral light temperature when comparing the White vs. Red room wall color condition. A statistically sig- nificant difference was noted in the warm light temperature for the high chro- matic 61 shade value in White vs. Black (p = 0.038) and White vs. Red (p = 0.005) room wall color condition comparisons. No significant differences were observed in White vs. Blue comparisons across any tested light temperatures (p > 0.185). Medium chromatic 66 shade value and low chromatic 81 shade value exhibited no statistical differences in any room wall color comparison considering light temperatures (p > 0.231). 8 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Table 3. ∆E00 mean and standard deviation values for high, medium, and low chromatic shade values considering the Biotone scale at different room wall color comparisons, light temperature, and tooth shades. White × Black White X Red White X Blue High Value (61) Cool light 0.21 (0.07) Ab 0.32 (0.10) Ab 0.50 (0.27) Aa Neutral light 0.57 (0.27) Aa 0.84 (0.03) Aa 0.61 (0.22) Aa Warm light 0.45 (0.31) ABab 0.38 (0.19) Bb 0.77 (0.21) Aa Medium Value (66) Cool light 0.70 (0.30) Aa 0.54 (0.45) Aa 0.47 (0.39) Aa Neutral light 0.20 (0.12) Aa 0.43 (0.12) Aa 0.32 (0.11) Aa Warm light 0.30 (0.16) Aa 0.67 (0.36) Aa 0.61 (0.10) Aa Low Value (81) Cool light 0.62 (0.40) Aa 0.68 (0.46) Aa 0.32 (0.29) Aa Neutral light 0.29 (0.16) Aa 0.40 (0.30) Aa 0.29 (0.14) Aa Warm light 0.44 (0.34) Aa 0.66 (0.39) Aa 0.58 (0.43) Aa Different uppercase in the same rows indicate significant between-group differences considering the light temperature (i.e., Neutral vs. Warm; Neutral vs. Cool; Warm vs. Cool) (p < 0.05); Different lowercase in the same columns indicates within-group differences considering the chromatic shade values for the Biotone scale (p < 0.05). Figures 3 and 4 illustrate the CIELab* coordinates’ means for the Vita Classical and Biotone shade-guide scales, respectively. Both scales showed a tendency toward greener hues for high chromatic shade values (B1 and 61 shades), while medium chromatic (A3 and 66 shades) and low chromatic (C4 and 81 shades) values leaned towards reddening. Both shade guides displayed a yellowing tendency for the b* coor- dinate. The L* coordinate in high-chromatic values (B1 and 61 shades) approached white, whereas it distanced from white in low-chromatic values (C4 and 81 shades). Medium-chromatic values (A3 and 66 shades) exhibited an intermediate L* value compared to high and low-chromatic values. 9 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Figure 3. Mean ± standard deviation ΔE00, CIE L* coordinate values considering (a) Biotone shade-guide scale and (b) Vita Classical shade-guide scale, for the different light temperatures (i.e. cool, neutral, warm), chromatic shade values (i.e. high, medium and low), and room wall colors (i.e. white, blue, red and black). Figure 4. Mean ± standard deviation ΔE00, CIE a* coordinate values considering (a) Biotone shade-guide scale and (b) Vita Classical shade-guide scale, for the different light temperatures (i.e. cool, neutral, warm), chromatic shade values (i.e. high, medium and low), and room wall colors (i.e. white, blue, red and black). 10 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Figure 5. Mean ± standard deviation ΔE00, CIE b* coordinate values considering (a) Biotone shade-guide scale and (b) Vita Classical shade-guide scale, for the different light temperatures (i.e. cool, neutral, warm), chromatic shade values (i.e. high, medium and low), and room wall colors (i.e. white, blue, red and black). Discussion This study evaluated the influence of light temperature and room wall color on ∆E00 val- ues of two different shade-guide scales using low, medium, and high chromatic shade values. The tested hypotheses were accepted since the extreme light temperatures (warm and cool) and darker room wall color conditions (black and red) yielded ∆E00 values with statistically significant differences in both evaluated shade-guide scales. Environmental illumination and external conditions are critical for tooth shade selec- tion in dentistry, significantly influencing the final color of restorations15-17. Previous reports have assessed ∆E00 and hue values considering different shade guides17,18, light temperatures8,19, and measurement methods20-23. However, to the best of our knowledge, no published studies have examined how light temperature and environ- mental characteristics (e.g., room wall color) influence final tooth shade selection. Natural daylight (averaging 6500K) is considered the best option for visual scale-aided color selection in dentistry, as it is the most efficient white light source6,10,18,24. How- ever, daylight is not always constant due to factors like time, weather, humidity, and pollution9. Thus, neutral light sources are good options for dental offices25. Our study showed that neutral light had less ΔE00 variability, as seen in Tables 1 and 2, where 11 Chaves et al. Braz J Oral Sci. 2025;24:e255791 neutral vs. warm and neutral vs. cool conditions did not show statistical differences. Our results showed significant variations in ΔE00 between different light temperatures for the Vita Classical scale, especially for the medium chromatic value (A3) between warm and cool light conditions. High chromaticity (B1) and medium chromaticity (A3) shades exceeded the clinical perceptibility threshold (ΔE00 > 0.8), indicating that these color differences are visible to more than 50% of the population. The results from Table 2 showed that for the Vita Classical scale, the simulated room wall colors did not produce statistically significant differences for the high chromatic B1 shade value. However, for medium (A3) and low (C4) chromatic val- ues, the differences were significant, particularly under cool light temperature in the white vs. black wall color condition. This suggests that wall color can influence color perception under cool light. For the Biotone scale, all ΔE00 values remained within the clinical acceptability limit (ΔE00 ≤ 1.8). The high chromatic 61 shade exceeded the clinical perceptibility threshold under neutral light temperature when compar- ing white vs. red wall color. Statistically significant differences were noted for the high chromatic 61 shade under warm light in white vs. black and white vs. red wall color comparisons. We observed significant variation in the high chromatic B1 shade compared to the A3 and C4 shades under warm vs. cool light temperature conditions using the Vita scale. This can be explained by the specific optical characteristics of the B1 shade. Known for its high luminosity, B1 reflects more light, making it particularly sensitive to changes in light temperature. Under warm light, B1 may appear brighter and less chromatic. Under cool light, B1 may appear darker and more saturated. Both shade guides showed a tendency toward greener hues for high chromatic values (B1 and 61), while medium chromatic (A3 and 66) and low chromatic (C4 and 81) values leaned towards reddening. The b* coordinate indicated a yellowing trend for all high, medium, and low chromatic values in both scales. The L* coordinate showed that high chromatic values (B1 and 61) approached white, while low chromatic values (C4 and 81) distanced from white. Medium chromatic values (A3 and 66) exhibited intermediate L* values compared to high and low chromatic values. The ΔE00 perceptibility and acceptability thresholds are 0.8 and 1.8, respectively15,26. In our experiment, all ΔE00 values were below the clinical acceptability limit, though some were above the clinical perceptibility limit, meaning these differences can be observed by more than 50% of the population. The highest ΔE00 value (0.98) was found in warm vs. cool light temperature conditions for the Vita shade-guide scale with the B1 shade. In dental offices, it is recommended to use a minimum illuminance of 500 lux21. In our study, the simulated environment achieved 445 lux, close to the standard recom- mendation, allowing comparison with a dental office. Regarding room wall color, the room’s atmosphere can influence human visual perception. High contrasts between the workspace and wall color require more visual effort for eye adaptation27. There- fore, the workspace wall color should have a harmonious composition to avoid these contrasts. Recent studies on wall color and ambient light show minimal influence on intraoral scanner performance25,28. 12 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Based on our findings, we recommend using neutral light temperatures (around 4000K to 5000K) and light-colored walls (soft whites or grays) for tooth shade match- ing to minimize ΔE00 variability. These recommendations aim to optimize environmen- tal conditions for tooth shade selection, improving accuracy and consistency in dental aesthetics. While our results provide valuable insights, caution is needed when apply- ing these findings to real-world settings. Future studies should explore how these environmental variables interact in more dynamically lit and decorated spaces com- mon in dental clinics. Ongoing research should also focus on developing new technologies in lighting and color measurement tools that better simulate natural daylight and provide more accu- rate color matching capabilities. Further studies are necessary to validate our findings and explore their effects in practical clinical scenarios, considering variables like dif- ferent types of artificial and natural lighting throughout the day. Our study had some limitations, such as the high level of environmental con- trol that cannot be fully replicated in typical dental offices. This ideal experimental setup for isolating variables does not fully represent the variability and challenges in everyday clinical environments, which may limit the direct applicability of our findings. However, some strengths include the frequent use of shade-guide scales for tooth shade selection in daily clinical practice. The color of the workspace is crucial due to its strong influence on the final restorative process. More studies are needed to determine the interaction between wall color and ambient light in tooth shade selection. The clinical effect of actual environment size should now be investigated, considering light temperature, wall color, stress, and visual fatigue as possible variables. In conclusion, within the limitations of this study, it was concluded that neutral light temperature produces lower ∆E00 values across all simulated room wall colors using the Vita Classical shade-guide scale. However, for the Biotone shade-guide scale, high-chromatic shade values (i.e., B1 and 66 shades) measured under neu- tral light exceeded the perceptibility threshold in the White vs. Red room wall color condition. Both shade-guide scales showed a reddish tendency (a* coordinate) in low- and medium-chromatic shade values (i.e., A3, 61, C4, and 81 shades), while high-chromatic values (i.e., B1 and 66 shades) exhibited a greenish hue. Additionally, a yellowing trend (b* coordinate) was observed across all chromatic shade values for both shade-guide scales. Acknowledgments The present study was carried out with the support of the Coordination for the Improvement of Higher Education Personnel - Brazil (CAPES) - Finance Code 001 Funding information Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Grant/Award Num- ber: Finance Code 001. 13 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Conflicts of interest None. Disclosure Statement The authors do not have any financial interest in the companies whose materials are included in this article. Author Contribution Eduardo Trota Chaves: software, formal analysis, investigation, writing – original draft, writing – review and editing, supervision, project administration, funding acquisition. Camila Raubach Dias: conceptualization, methodology, software, formal analysis, investigation, resources, data curation, writing – original draft, writing – review and editing, supervision, project administration, funding acquisition. Fabiola Jardim Barbon: conceptualization, methodology, software, validation, formal analysis, investigation, resources, data curation, writing – original draft, writing – review and editing, supervision, project administration, funding acquisition. João Pedro do Couto Caetano: investigation, writing – original draft, writing – review and editing, supervision, project administration, funding acquisition. 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White Wall Black Wall Red Wall Blue Wall High Value (B1) CIE L* Cool light 78,2 (0,8) Bb 79,3 (0,2) Aa 78,6 (0,3) Bab 78,6 (0,1) Bb Neutral light 78,8 (0,1) Aa 78,6 (0,2) Ab 78,8 (0,2) Aa 79,0 (0,6) Ab Warm light 79,3 (0,8) Aa 78,9 (0,2) Ab 78,5 (0,1) Bb 79,3 (0,0) Aa CIE a* Cool light -1,4 (0,0) BCa -1,4 (0,0) Bb -1,4 (0,1) Ca -1,3 (0,0) Aa Neutral light -1,4 (0,1) Ba -1,3 (0,1) Aa -1,4 (0,1) Ba -1,4 (0,0) Bb Warm light -1,4 (0,0) Aa -1,4 (0,0) Ab -1,4 (0,0) Aa -1,4 (0,0) Ab CIE b* Cool light 11,5 (0,7) Aa 12,3 (0,1) Aa 11,8 (0,3) Aa 11,8 (0,1) Ab Neutral light 11,8 (0,1) Ba 11,7 (0,4) Bb 12,0 (0,2) Aa 11,7 (0,2) Bb Warm light 12,0 (0,3) ABa 11,5 (0,4) Cb 11,9 (0,1) BCa 12,3 (0,1) Aa Medium Value (A3) CIE L* Cool light 76,7 (0,2) Aa 76,5 (0,2) Aa 76,2 (0,2) Bb 76,0 (0,1) Bc Neutral light 76,1 (0,1) Bb 76,2 (0,1) ABb 76,1 (0,3) Bb 76,4 (0,2) Ab Warm light 76,5 (0,3) Ba 76,4 (0,3) Bab 77,5 (1,4) Aa 76,7 (0,2) ABa CIE a* Cool light 0,1 (0,1) Aa 0,1 (0,0) Ab 0,2 (0,1) Aa 0,1 (0,1) Aa Neutral light 0,0 (0,0) Bb 0,2 (0,0) Aa 0,2 (0,1) Aa 0,1 (0,1) Aa Warm light 0,1 (0,1) Ba 0,1 (0,1) Bb 0,3 (0,2) Aa 0,2 (0,0) Aa CIE b* Cool light 22,3 (0,1) Aa 22,4 (0,1) Aa 21,7 (0,4) Bb 21,7 (0,3) Ba Neutral light 21,0 (0,3) Bb 22,1 (0,2) Ab 22,2 (0,3) Aa 22,0 (0,4) Aa Warm light 22,3 (0,2) Aa 21,8 (0,4) Bb 22,1 (0,6) Aa 22,2 (0,1) Aa Low Value (C4) CIE L* Cool light 64,9 (2,1) Ca 65,8 (0,1) Aa 65,4 (0,2) Ba 65,1 (1,7) Ba Neutral light 65,8 (0,0) Aa 65,9 (0,4) Aa 65,5 (0,1) Ba 65,8 (0,1) Aa Warm light 65,7 (0,2) Ba 65,9 (0,1) Aa 65,5 (0,1) Ca 65,7 (0,1) Ba CIE a* Cool light 1,1 (0,1) Cb 1,2 (0,1) Ba 1,3 (0,0) Aa 1,3 (0,1) Aa Neutral light 1,1 (0,0) Bb 1,2 (0,1) Aa 1,2 (0,1) Bb 1,3 (0,0) Aa Warm light 1,3 (0,0) Aa 1,1 (0,1) Bb 1,3 (0,0) Aa 1,3 (0,0) Aa 17 Chaves et al. Braz J Oral Sci. 2025;24:e255791 CIE b* Cool light 24,0 (0,2) Aa 24,2 (0,0) Aa 23,8 (0,1) Ba 23,6 (0,6) Bb Neutral light 23,6 (0,0) Bb 23,7 (0,5) Bc 23,8 (0,2) Ba 24,0 (0,1) Aa Warm light 23,8 (0,1) Bb 24,0 (0,2) Ab 23,9 (0,0) ABa 24,0 (0,0) Aab Different uppercase in the same rows indicate significant between simulated room wall colors differences considering the light temperature (i.e., Neutral vs. Warm; Neutral vs. Cool; Warm vs. Cool) (p < 0.05); Different lowercase in the same columns indicates within-group light temperatures chromatic shade values for the Vita Classical shade-guide scale (p < 0.05). 18 Chaves et al. Braz J Oral Sci. 2025;24:e255791 Sup Table 2. Mean and (standard deviation) values of the CIE L*, a* and b* coordinates from high, medium and low values refer to the Biotone shade-guide scale for the light temperature in simulated room wall colors environments. White Wall Black Wall Red Wall Blue Wall High Value (61) CIE L* Cool light 82,6 (0,2) Aa 82,4 (0,2) Aba 82,2 (0,2) BCa 82,0 (0,4) Cc Neutral light 81,9 (0,4) Bb 82,8 (0,7) Aa 81,9 (0,2) Bb 82,5 (0,2) Ab Warm light 82,1 (0,1) BDb 83,8 (3,3) Ca 81,9 (0,4) Dab 85,7 (3,9) Aa CIE a* Cool light -0,5 (0,0) Bb -0,6 (0,1) Bb -0,5 (0,1) Ba -0,3 (0,1) Aa Neutral light -0,3 (0,0) Aa -0,3 (0,1) Aa -0,7 (0,2) Cb -0,5 (0,1) Bb Warm light -0,6 (0,1) Bb -0,8 (0,3) Cc -0,5 (0,1) Aa -0,4 (0,1) Aab CIE b* Cool light 37,9 (0,3) Ab 37,7 (0,6) Aa 37,4 (0,6) Aab 38,1 (0,7) Aa Neutral light 39,2 (0,1) Aa 37,9 (1,5) Ba 36,3 (1,2) Cb 38,0 (0,6) Ba Warm light 37,2 (0,7) Bb 34,7 (4,3) Bb 37,7 (0,3) Ba 38,6 (0,4) Aa Medium Value (66) CIE L* Cool light 76,6 (0,5) Aa 76,6 (0,2) Aa 76,6 (0,4) Aa 77,7 (0,8) Aa Neutral light 76,8 (0,0) Aa 76,8 (0,3) Aa 76,9 (1,5) Aa 76,9 (0,5) Aa Warm light 76,8 (0,4) ABa 76,5 (0,1) Ba 76,5 (0,3) Ba 77,6 (0,9) Aa CIE a* Cool light 1,9 (0,2) Aa 1,5 (0,3) Bb 2,0 (0,1) Aa 1,9 (0,3) Aa Neutral light 2,0 (0,0) Aa 2,0 (0,1) Aa 1,9 (0,2) Aa 1,9 (0,1) Aa Warm light 2,0 (0,1) Aa 1,8 (0,1) Ba 1,7 (0,2) Bb 1,7 (0,2) Bb CIE b* Cool light 43,7 (1,4) Aa 41,9 (1,8) Bb 44,1 (0,3) Aa 43,0 (2,2) Aa Neutral light 44,3 (0,0) Aa 44,1 (0,4) Aa 43,1 (2,6) Aa 44,0 (0,3) Aa Warm light 44,2 (0,1) Aa 44,1 (0,4) Aa 42,7 (1,2) Bb 42,4 (1,4) Ba Low Value (81) CIE L* Cool light 68,4 (0,2) Aa 68,5 (0,2) Aa 68,2 (0,0) Ba 68,2 (0,1) Bc Neutral light 68,5 (0,2) Aa 68,5 (0,1) Aa 68,0 (0,2) Ba 68,5 (0,1) Ab Warm light 68,5 (0,2) Ba 68,4 (0,1) Ba 68,2 (0,1) Ca 68,9 (0,2) Aa CIE a* Cool light 5,1 (0,2) Aa 4,7 (0,3) Bab 4,8 (0,2) Ba 5,0 (0,1) Aa Neutral light 4,9 (0,1) Aba 4,9 (0,1) Aba 4,8 (0,2) Ba 5,0 (0,1) Aa Warm light 4,9 (0,2) Aa 4,6 (0,2) Bb 4,6 (0,3) Ba 5,0 (0,1) Aa 19 Chaves et al. Braz J Oral Sci. 2025;24:e255791 CIE b* Cool light 50,4 (0,6) Aa 48,3 (2,0) Ba 48,4 (1,7) Ba 49,6 (0,4) Aba Neutral light 49,9 (0,5) Aab 49,1 (0,1) Ba 48,9 (1,3) Ba 50,1 (0,7) Aa Warm light 49,1 (0,2) Ab 48,5 (1,5) Aba 47,4 (2,0) Ba 50,1 (0,5) Aa Different uppercase in the same rows indicate significant between simulated room wall colors differences considering the light temperature (i.e., Neutral vs. Warm; Neutral vs. Cool; Warm vs. Cool) (p < 0.05); Different lowercase in the same columns indicates within-group light temperatures chromatic shade values for the Biotone shade-guide scale (p < 0.05).