Pure colored substances mostly exhibit a single peak (i.e. ?max) in the visible; therefore the simple rules of complementary colors apply. Mixtures are a little more complicated. When you were in grade school you learned that by mixing yellow (?max = 450 nm) with blue (?max = 605 nm) you get green. Describe why this is based on the wavelength range that is transmitted. What color would you see if you mixed the two solutions with ?max = 520 and ?max = 610?