# Color Brightness Recognition of Extremely Severe Amblyopia Children in an Indoor Environment
## 2 Methods
### Color Brightness Test Sample  
#### 2.4.1 Selection of Experimental Colors  
These five colors--red, yellow, green, blue, and purple--hold pervasive applications across various facets of daily life. Red, with its high contrast and attention-grabbing properties, is a universal choice for signaling emergencies, danger, or prohibition, evident in traffic lights and stop signs. Yellow, recognized for its visibility under low-light conditions,  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Serial Number** & **Age** & **Gender** & **Class of Vision** & **Left Vision** & **Right Eye Vision** \\ \hline N1 & 6 & Female & Extremely severe & 0.1 & 0.15 \\ N2 & 8 & Female & Extremely severe & 0.25 & 0.1 \\ N3 & 12 & Female & Extremely severe & 0.1 & 0.1 \\ N4 & 13 & Female & Extremely severe & 0.02 & 0.1 \\ N5 & 13 & Male & Extremely severe & 0.02 & 0.12 \\ N6 & 7 & Male & Extremely severe & 0.1 & 0.2 \\ N7 & 10 & Male & Extremely severe & 0.2 & 0.15 \\ N8 & 12 & Male & Extremely severe & 0.2 & 0.2 \\ N9 & 11 & Male & Extremely severe & 0.1 & 0.15 \\ N10 & 12 & Male & Extremely severe & 0.1 & 0.25 \\ \hline \hline \end{tabular}
\end{table}
Table 1: List of experimental subjects.  
is a prevalent choice for warnings or alerts, as seen in cautionary signage. Green, often linked with safety or permission to proceed, is commonly utilized in green traffic lights and evacuation routes and is generally regarded as a calming and reassuring color, minimizing the likelihood of misinterpretation. Blue, while less frequently employed, can be found in informational prompts or directional guidance, such as in specific traffic signs. Purple, a composite color derived from red and blue, is less commonly utilized in daily life but is included in China's color blindness tests alongside the aforementioned colors. The selection of lower-brightness shades of purple by visually impaired children may suggest a diminished sensitivity to composite colors, which could indicate a potential risk of latent color vision deficiency and potentially exclude them from the experiment. The significance of these five colors in the daily lives of visually impaired children is underscored by the fact that ambiguous hues, such as orange and pink, are less appropriate for them. Given that color purity significantly influences hue perception, this study focuses exclusively on brightness in its examination of color.  
The authors categorized the 11 levels of brightness for the 5 colors into 6 color numbers based on the RGB color attributes, as illustrated in Figure 1. The colors labeled as No. 1 are standard red (255, 0, 0), medium yellow (255, 217, 0), standard blue (0, 0, 255), standard green (0, 255, 0), and standard purple (128, 0, 128). The choice of medium yellow over standard yellow (255, 255, 0) was deliberate, given the prevalence of medium yellow in China's blind lanes and vehicle turn signals. These five colors were specifically selected for color blindness testing in China and hold practical significance in everyday life.  
The authors categorized colors based on brightness into six groups. Group 1 and Group 4 are designated as the standard-color group, characterized by strong hue properties and distinct color tendencies. Groups 2 and 3 constitute the high-brightness group, where the standard colors have been adjusted with the white attribute. Groups 5 and 6 form the low-brightness group, with the standard colors modified by adjusting the black attributes. This grouping of brightness levels will facilitate the analysis of the specific effects of lighting and distance on color recognition in future experiments.