Gel coat pigments/colorants are widely available, remember that red, green ,yellow + black make up all colors. It takes some guessing, best to "sneak up on it" a little goes a long way. Only mix a small amount like one or two ounces until you get the right recipe ratio then make a quart. It cures slightly different in color than when wet. An artist whether oil
or watercolor would be a good resource for color match. Gel coat comes unwaxed and waxed, for repairs
you want waxed or it won't kick. to spray with a preval add styrene to thin.