Breakwater,
Sorry I don't have any good picture of my Tornados. If the dark boat you saw had Marstrom hulls the temperature dosen't really matter. These boats are built of s-glass prepreg and baked in an oven. So the heat distortion tepmperature of the resin in in excess of 250 degrees or 350 degrees depending on the material used. For older hulls made of wet layup polyester, dark colors could be an issue.

Kevin