How do you add different layers of color to stamp concrete??

Question:I am interested in doing another stamp concrete project at my home. Looking at doing a red clay brick stamp walkway. I want to color it so the brick is bright red and the joints gray. I suppose I can leave the joints cement color but my question is how to get the bricks red and not the joints? Is it painted on or what? I want to know the process of adding different colors on top of it without coloring the joints?

Answers:
r u stamping this u'rself...? the only way I can think to do it... they use concrete dye so u can lay the stamp then put the powder over it so the brick would b colored & not the grout which i would leave u'r cement color.

Other than that, if u opt to paint... they do carry concrete paint/stain which would work. Let me know how it goes... I'm really interested...wow...