Check the Starcraft Glass boat site, would be your best bet.
What site is that?
Here is my current idea. One of the Gel Coat companies can match a piece of Gel Coat or a paint. So I am hoping if I can get a latex to match (maybe scan the hull) I can send a sample to get pre-matched Gel Coat.
Autobody supply stores can scan your color and give an accurate mix in 'their' paint or a chart number you can use to find the best/closest replacement color.
Dupont (IMHO) is close to the best paint.
As for latex?...that doesn't belong on a boat!