## 3 Results and Discussion  
### Results of Colour Preference and Lighting Environment Perception  
The overall results of the colour preference (fruit and vegetable; skin tone) and atmosphere perception (_Unconfortable/Confortable_, _Cool/Warm_, _Negative/Active_, and _Tense/Relaxed_) experiments are shown in Figure 8. The rating trends for the four scenarios (i.e., two sessions in two experiments) are consistent and the scores for the scenarios in Exp.2 are significantly higher than the scores in Exp.1. According to a Mann-Whitney U test, there is no significant difference between the results for the experienced (Group A) and the inexperienced subjects (Group B) in Exp.2, in terms of the six aspects (\(p\) values > 0.05, with a range from 0.12 to 0.89), which implies that any practice effect for these visual attributes is very small. Thus, in this section, the results of Group A and Group B in Exp.2 were combined for analysis. The statistical significance (\(\alpha\) = 0.05) of the observed effects of the lighting environment, test trial (i.e., first trial in Session 1 and the second trial in Session 3), gender, as well as the interaction effects, was analysed by multivariate analysis of variance (MANOVA) tests using SPSS software. The results are listed in Table 3 and show that the lighting environment has a significant effect (\(\alpha\) = 0.05) on all aspects except the preference rating of the fruit and vegetables, whereas no significant effects of test trial and gender were found. Specifically, the insignificant impact of test trial in Table 3 indicates that the visual fatigue caused by the two-hour self-study period in Session 2 did not remarkably influence the visual judgments. It is noteworthy that the \(p\) values for gender in terms of _fruit and vegetables preference_, _skin preference_, _Unconfortable/Confortable_, and _Negative/Active_ are close to the threshold of \begin{table}
\begin{tabular}{c c c} \hline \hline
**Scales** & **Descriptions in English** & **Descriptions in Chinese** \\ \hline
1 & Extremely alert & \\
2 & Very alert & \\
3 & Alert & \\
4 & Rather alert & \\
5 & Neither alert nor sleepy & \\
6 & Some signs of sleepiness & \\
7 & Sleepy, no effort to stay awake & \\
8 & Sleepy, some effort to stay awake & \\
9 & Very sleepy, great effort to keep & \\  & awake, fighting sleep & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Overview of the Karolinska Sleepiness Scale (KSS). Figure 8: Results of colour preference rating and lighting environment evaluation with the error bars representing 95% confidence intervals (F&V—Fruit and Vegetables). significant level (\(\alpha\) = 0.05), which suggests the need for further investigation on gender difference in future work. None of the other two-way or three-way interactions among the three fixed factors, lighting environment, test trial, and gender, were significant (\(p\) values were between 0.14 and 0.97 with a mean of 0.73). After the Bonferroni correction (\(\alpha\) = 0.05/6 = 0.0083) to account for the multiple significance tests, lighting environment remained significant for _skin preference_, _Uncomfortable/Comfortable_, and _Cool/Warm_. The partial eta-squared values (\(\eta^{2}\)) revealed the effect size of each factor (Table 3). For most of the visual attributes, lighting environment had a major effect on the subjects' evaluations, since the \(\eta^{2}\) values were larger than those for the test trial and gender (with an exception for preference of fruit and vegetables). As shown in Figure 8, the preference ratings of fruit and vegetables are different to those of skin tone. Such a result is consistent with the findings of [PERSON] et al. [55], which aimed to evaluate the differences in appreciation for fruit and vegetables, packaging materials, and skin tone of the hand. These results might be attributed to the difference of colour saturation enhancement between multicoloured objects (fruit and vegetables) and single colour object (skin tone).