Have you ever thought, why the base suits for kigurumi, are most flesh color zentai suits? I believe the main reason is, the suit worn inside, is playing the role of the skin, and the flesh color's most match with that. There are all other different skin colors, but the kig's originated in Asia, so it becomes the mainstream.
|Flesh Lycra Spandex Zentai Suit|
|The Flesh Zentai Suit is More Obvious at This Photo|