Maple leaves are actually red and green in all seasons. When light bounces off the green pigments in the chlorophyll, it blinds us to the red. The chlorophyll leaches out of the leaves when the weather turns cold in the fall, and we finally see the red. What humans see as red, another animal might see in shades of black and white or as a completely different color. Some animals see colors humans can't.
Culture makes a difference in color perception, too.
Until extensive contact with the West, the Japanese had no word for the color blue. No one can say. Poets look differently at the world. Artists do, too. Very much like our visual sensory system, they look carefully, tear apart what they see, then reconstruct visual meaning.