Basic Information
Something of a fantasy meta-trope, this is the concept that any given species will have a variety of different subtypes with noticeably differing powers and mostly told one from another by their colour. The potential for unfortunate implications is usually overlooked. These may be mutually infertile subspecies, true-breeding races or a pseudo-genetic lottery depending on setting.
In extreme cases the colour of a given race may determine its allegiances, the most obvious being the "black equals evil" meme for unicorns, pegasi and the like, but similar things may occur for elemental alignments and, more generally, for dragons.