If you’re as clumsy and careless as I am, you’ll have experienced potentially thousands of bruises over the course of your life – and even those that don’t have the coordination of a newborn calf will have had a bruise at some point. So you’ll have probably noticed your bruise changing color.

Bruises can appear in a rainbow of colors: black, reddish, purple, green, yellow, and blue. They will also fade and change as time passes from the initial incident. But why?

Take a look at this video by SciShow to find out: