There is no such thing as "nature" - sorry!
God created these contradictory things to tell us something and it is for us to find out why.
In high-school chemistry, I learned that color is a characteristic of chemicals.
Color in living things are used foe many of their life events that God can create and orchestrate.
Some flower looking plants are actually leaves.
Poisonous snakes have vivid colors to attract its preys.
Other creatures use color to protect themselves.