So the boat I just bought has a couple of old screw holes from the speedo that I took off and 2 small chips in the gel-coat on the transom that I would like to fix. I don't care about matching the flake but I would like the patches to be black. You can see the silicone from the speedo obviously and the chips are on the bottom edge below the drain hole. Since marine-tex isn't black is there something else available?