## 1 Introduction
This method assesses the color quality of light on the basis of several parameters: general color fidelity index (\(R_{f}\)) [32; 33; 34] (currently is the most accurate measure of light color fidelity [26; 35; 36]), color gamut area index (\(R_{g}\)) (a metric that quantifies the average change in chroma across a color gamut), and local red chroma (saturation) shift (\(R_{\rm cs,\,\mu 1}\)) specified by hue angle bin. This classification system (see Table 2) defines four priority levels of color preference: P1, P2, and P3, and out-of-class, the latter corresponding to insufficient color rendering properties. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Country and Region** & **Australia and New Zealand** & **European Union and United Kingdom** & **United States** \\ \hline \multirow{4}{*}{CCT requirements} & \multirow{4}{*}{3300 K \(\leq\) CCT \(\leq\) 5300 K} & Nominal CCT & Nominal CCT \\  & & 4000 K \(\leq\) CCT \(\leq\) 5000 K & 4000 K \(\leq\) CCT \(\leq\) 5000 K \\ \cline{1-1}  & & Acceptance range & Acceptance range \\ \cline{1-1}  & & 3710 K \(\leq\) CCT \(\leq\) 5312 K & 3710 K \(\leq\) CCT \(\leq\) 5312 K \\ \hline \multirow{4}{*}{general and ward areas} & \multirow{4}{*}{\(\geq\)80} & No \\ \cline{1-1}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \(\geq\)80 \\ \cline{1-1} \cline{3-4}  & & & (for exam areas) \\ \cline{1-1} \cline{3-4}  & & & \(>\)90 \\ \cline{1-1} \cline{3-4}  & & & (for surgery) \\ \hline \multirow{4}{*}{Special requirements} & \multirow{4}{*}{Cyanosis observation: COI \(\leq\) 3.3} & CCT requirements for \\ \cline{1-1}  & & general lighting in the \\ \cline{1-1}  & & COI \(\leq\) 3.3 & examination rooms \\ \cline{1-1} \cline{3-4}  & & 3710 K \(\leq\) CCT \(\leq\) 5312 K & 3710 K \(\leq\) CCT \(\leq\) 5312 K \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Standard requirements for light sources used in medical examination rooms. Until now, fluorescent lamps (FLs) have been widely used for interior lighting, particularly in public building spaces. The spectral power distribution (SPD) of commercially available FLs exhibits narrow peaks resulting from mercury (Hg) emission lines and phosphor-based emissions (refer to Figure 2a). The chromaticities of these FLs (Figure 2b) meet the ANSI chromaticity tolerance requirements for nominal CCT [39; 40] given by MacAdam standardized ellipses (the range in which all colors around a reference point in a chromaticity diagram are indistinguishable by the average human eye MacAdam called as \"1-step ellipse\"). Any point on the boundary of a \"1-step\" ellipse drawn around a target represents one standard deviation from the target. Due to this, these ellipses are also known as the \"Standard Deviation of Color Matching\" (SDCM). By more restricted categorization, the document [39] establishes a \"4-step\" SDCM ellipses categorization (the boundary represents four standard deviations from the target chromaticities) and a \"5-step\" SDCM ellipses categorization (the boundary represents five standard deviations from the target chromaticities) with less restricted categorization requirements [40]. Their chromaticities are presented in Figure 2 by the magenta and yellowish (lime yellow) stars for lamps applicable in Australia/New Zealand and by magenta stars for lamps used in Europe, the United Kingdom, and the United States in medical examination rooms. \begin{table}
\begin{tabular}{c c c} \hline
**Class P1 ”Best”** & **Class P2 ”Good”** & **Class P3 ”Acceptable”** \\ \hline \(R_{f}\geq 78\) & \(R_{f}\geq 74\) & \(R_{f}\geq 70\) \\ \(R_{g}\geq 95\) & \(R_{g}\geq 92\) & \(R_{g}\geq 89\) \\ \(-1\%\leq R_{cs,H1}\leq 15\%\) & \(-7\%\leq R_{cs,H1}\leq 19\%\) & \(-12\%\leq R_{cs,H1}\leq 23\%\) \\ \hline \end{tabular}
\end{table} 
Table 2: The boundaries of categorization parameters according to the color preference criteria ANSI/IES TM 30-20 method priority levels (class) [26].