Hopefully you'll get suggestions but the basic issue with signs is that we create their meanings. Usually these are encoded in culture (as in dress codes). The basic yin yang is associated with a particular philosophy and in context represents positive and negative balance and, as meanings go, the striving behind achieving that balance (connotations). As a principle it now reaches beyond its origins but for most people the meaning is similar.

Its colouring is something we have to decipher for ourselves. The original black and white again are signs conventionally associated with negative/positive - dark/light. For some their meaning is female/male. Technically they compliment. Yellow and orange aren't complimentary in terms of light/colour but may signify something different.

Let's see what people say.