颜色检测

烟圈

Solution S
Dissolve 2.50 g in ethanol (96 per cent) R and dilute to 25 mL with the same solvent.
Appearance of solution
Solution S is clear (2.2.1) and not more intensely coloured than reference solution BY5 (2.2.2,
Method II).
BP中颜色与澄明度检测中BY5对映的是中国药典哪个颜色对照？怎么配制的？求路过大佬帮帮忙！