CONTINUOUSWAVE

Q1: is the gel coat color of a 1976 15-footer "white" or Desert Tan?

Ans[wering my own question]: DESERT TAN.

Cf.: https://continuouswave.com/whaler/reference/15/

To assess a gel coat color, the surface must be clean, must have oxidation removed, must be polished, and must be viewed in sunlight at midday. Having a sample of a pure titanium white color will provide a good reference for making a facile comparison between the hue of Desert Tan and a pure white.