Use your fingers to pat on dark blue around the rim of the black latex. Start out thick around the edge of the latex and gradually apply less as you move away from the wound. Apply red over the blue areas, blending into your skin color at the outside of the bruise.
Now add blots of yellow at choice spots, using your finger again to lightly apply the makeup. The yellow blotches will give the bruise a more realistic look. Next, let's add some fake blood.