Best way to match skin color

Hey guys,

Suppose I combine the head of a character with the body of another character. But they have different skin tone. How can I match, let’s say, the skin tone/color of the head with of the body’s? Thank you.

There is an eye-dropper tool in the material color selection window for copying a color from the viewport. I’m not sure how to use it but that’s what it’s for.