It would also be an excellent name for pigment molecules (like chlorophyll or carotenoids) that absorb light energy and become charged in order to provide energy for plant life. These pigments absorb certain wavelengths better than others (chlorophyll absorbs red and blue the best) because of the range of wavelength they work best at. The colours that are not absorbed by the pigment reflect back to our eyes to form the colours that we see. In the case of carotenoids, the rejected light that bounces back ends up being orange in most cases, which is why carrots look funny and make me laugh.