I just did a repair to a small ding (well hole actually) in my Tornado about 6 inches up from the keel line midway from the forebeam to the bow. The damage happened while lauching off my new trailer...boat blew sideways and hit the fender mount bracket edge. Only the outer skin of the hull was punctured, through to the foam, about 1/4" diameter.

Since my boat is painted (previous owner) a slight off-white grey, using straight white gelcoat as a finish would stick out like a sore thumb (or quite possibly a VERY sore hand blown apart by homebrew chemistry). Got a quote from the B.Y. repair guy...$600!!!!?!? So, there went another weekend for me. Used West System epoxy (whole boat is epoxy based) & light weight filler pl;us a little heavier density fairing filler for strength to fill the hole & surface scrape. I then used West Marine's gelcoat color match kit. It comes with a toothpast tube of clear gelcoat and a set of color tinting agents. I used a bit of white and a very slight amount of black to give a very close match. Used a little extra plus a bit more black tint to make a chip repair to my darker grey non-skid deck. Just "stippled" the surface a bit and sanded off the peaks later to give a real close match to texture.
Still got to do final fairing/polishing on the repair.

BTW, why do all the polyester based resins sold in West Marine state "Not to be used on epoxy"? I've never found any problem here.

Mike.