White reflects the sun, as do light-colored decks. Teak decks are pretty, and make great non-skid, but they are impossible to walk on in the heat. The same goes for a colored hull. Just imagine that beautiful dark blue sailboat, with blue awnings, and teak decks. That boat will be at least ten degrees hotter down below than a white boat, with white awnings and light colored decks.
Most people think it's white.
The light gray doesn't have the glare that white does, and is easy to keep clean. Irish Mist has full awnings and a large hard bimini. It is very important to have an awning for the fore deck, and covers for any large windows. We use white Sumbrella for the sunshades, and Textiline for the window covers. Textiline is a plastic mesh that you can see through, but still allows light to come through.