Well, I wouldn't rule out any logo based on the color, however, bear in mind that the logo will be site-wide, so it will not only show up on this message board.
If I were going to lean in any direction, I guess I would tilt towards the red and orange spectrum, simply because most corns tend to exhibit those colors. Of course, some genetic variants will not, but in most people's minds if you say 'corn snake' those would be the colors most commonly associated with this animal.