From lasers, to grow lights, and tanning beds, examples are all around us that demonstrate how light affects life.
Not only does does intensity matter, so too does color. Plants respond differently to different colors, growing broader leaves, for example, when exposed to certain colors of light. Our bodies, too, react, especially to blue light which triggers melatonin production.
On-going research is studying the effects of light and color on our bodies and our world.