What do you get if you mix a black with blue and you add green?

The color you would get when you mix a royal with a black depends on your mixture. If mixing only a small amount of black into the royal, you would get a darker, duller royal. If, say, you used equal parts blue and black, you would get a black, because black is dominant. However the black that you get could be a "livelier" black as opposed to a flat, dull black.