There are very few guild line for color selection in universal design. However, as we age we lose large percentage of our eye’s capability to receive light. Therefore, it is very important not only to choose a beautiful color but also a high contrast color in universal bathroom design.
Sauce:George A. Covingto and Bruce Hannah, Access by Design, Van Nostrand Reinhold, 1997.
From: Yu-Huan Wang
Workplace Design Principles 