Glow in the Dark Nuclear Soap
Available at ThinkGeek
Contains (bars) uranium (glows green), plutonium (glows blue), and a fallout shelter sign (glows white). Of course, it doesn't actually contain any of those things.
Actual ingredients: Coconut oil, castor oil, safflower oil, kosher vegetable glycerin, purified water, sodium hydroxide, sorbitol, sorbitan oleate, soy bean protein, zinc sulfide, copper chloride, color, fragrance.