The sky. The grass. The earth. The oceans. Their rich colors are a joy to behold.
On bright, sunshiny days, color lifts us up. On dark, stormy days it subdues us. This demonstrates that color clearly has an effect on us.
And yet color is an afterthought—if thought of at all—in training. This is unfortunate, because people see color before they absorb content; every color has a unique wavelength; and our brains respond uniquely to different colors.