Why do flowers have colors?
The short answer
Flower colors can help visiting animals find a flower. Floral pigments can act as signals involved in pollination, while also helping protect plant tissues from strong light.
How it works
Several pigments, including anthocyanins and carotenoids, contribute to petal color. The color we see depends on the kinds and amounts of pigments, how they combine, and the lighting conditions.
In some flowers, patterns of ultraviolet reflection and absorption, invisible to humans, may help bees and other pollinators locate the flower center or nectar. Not all flowers have ultraviolet patterns, and their appearance and role can differ among pollinators.
A familiar example
Flowers can change color as they open or after pollination. These changes can result from processes such as pigment production and breakdown, but they do not occur in every flower.