Gel coat repair
I used gel coat repair paste on my C30, and various tubes of coloring agent until I got a color close to the existing non-skid color. The key to color matching for me was to first go to a paint store (actually I sent my wife), and pick up all the paint chip sample cards that were close to the existing deck color. The I held each card out on the deck, on cloudy and sunny days, until I found a color that I think matched. Then I mixed the gelcoat and various colors, without the catalyst, in a baby-food jar until the color matched the card. The excess color-matched gelcoat is stored in the jar if I ever need more colored gelcoat, when I can take out just what I need. It was easier to color match while sitting down in a work area (with newspapers spread around, paper towels, etc. as it could get messy) than it would be out on the deck, so the color chip cards helped with that. Just hold the color card up to the side of the jar until the color matches.
