Photosynthetically active radiation the predominance of chlorophyll is autumn, when chlorophyll is degraded (because it contains N and Mg) but the accessory pigments are not (because they only contain C, H and O) and remain in the leaf producing red, yellow and orange leaves. In land plants, leaves absorb mostly red and blue light in the first layer of photosynthetic cells because of Chlorophyll absorbance. Green light, however, penetrates deeper into the leaf interior and can drive photosynthesis more efficiently than red light. Because green and yellow wavelengths can transmit through chlorophyll and the entire leaf itself, they play a crucial role in
Pigment purposes, including camouflage, mimicry, aposematism (warning), sexual selection and other forms of signalling, photosynthesis (in plants), as well as basic physical purposes such as protection from sunburn. Pigment color differs from structural color in that pigment color is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well. Pigment A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This