Why can't we see colors well in the dark?

Photo shows a silouetted figure standing at the edge of a wood at night and pointing a lit flashlight toward one clump of trees.

If you've ever gotten dressed in the dark and later realized that the shirt you were wearing was not the color you thought it was, you're not alone. Identifying colors can be challenging in the dark, and even in low light, different colors can look remarkably similar. 

But why is it harder to discern colors in the dark than it is in bright light?