The differences in populations are
(Colors)
(Look)
(Shape)
And (Form)
The slight color can be important because of camouflage.
The color can also make the organism look like a different animal.
Lets put snakes for example...
there are also some harmless snakes that are often confused with the coral snake, the shovel-nose snake, the scarlet kingsnake, the Florida scarlet snake, the Pueblan Milk Snake, and other snakes that look like coral snakes.
They do this so they look like a very dangerous animal and dont get hunted.