These ram horns work well under any color.
Ram Horns (Comes as pair)
Made of a closed cell foam similar to that used in thigh pads so they can be used in any game condition. Although they were originally made for thigh pads, treDCALs can stick to the plastic of hard shell girdles and other foam rubber materials. Unfortunately, they are not meant to stick to fabric. treDCALs work best under lighter colored clothing but they do work under darking colored clothing by showing the outlines of the image.