The colours of plants and animals have various functions. Chlorophyll is the green pigment used to collect light energy for photosynthesis in plants. Many colours on plants and animals work to change the behaviour of animals. They can be seen, and they act as a means of camouflage, warning or attraction (pollination; mating).
Pigments are different from structural colors. Pigments look the same from all angles. Structural color is the result of reflection or iridescence. For this reason, structural colors look different from different viewing angles. As an example, the wings of butterflies commonly use structural color.