SEC: Why are Leaves Not Black?

Biology students ground up different types of leaves from the TIS forest area with a mortar and pestle in 95% isopropanol to extract leaf pigments. (A couple of students had experience wielding a mortar and pestle in the kitchen as well.) The pigment solution was diluted with water and placed in a spectrophotometer which measures absorbance of light across the visible light spectrum. Although all of the leaves saw a broad peak of absorption in the violet wavelengths and a smaller, narrower peak in the red wavelengths which are characteristic of chlorophylls a and b, the wavelengths of maximum absorbance and the peak heights varied slightly with the type of leaves used. Green and yellow wavelengths were absorbed less as those light colors are mostly reflected by green plants. Higher energy violet/blue wavelengths and lower energy red wavelengths are the energy source that powers photosynthesis. So why are leaves not black to absorb all wavelengths of visible light to capture more energy for photosynthesis? Think about the last time you wore all black in the summer.