More information: Yunyi Zhu et al, PortaChrome: A Portable Contact Light Source for Integrated Re-Programmable Multi-Color ...

The team did tests on mice, fixing the brightness to high or low and switching the colour from blue to yellow. Bright light of either colour was stimulating, rather than restful, as expected.

Claude Monet used the impasto technique to describe the texture and light of his subjects. In his series of paintings of Rouen Cathedral he changed his technique to show different light conditions.