Originally Posted by Scummbuddy
Are we sure its not that color because he's just wet?
That was my first thought too.
However, this is only during the diving sequence. It is white again when swimming around.
Also I took a look at the game resources, and it looks like a bug to me. While the game has colors 192 - 207 reserved for Guybrush so light effects can be applied without affecting background or other actors. This particular gray though is color 63.
Also the colors 192 - 207 are already adjusted to give him a wet look.