well you could always make a circle model and then map it to this, use white as its base color and then add alpha dds to show up the rest of the symbol....theres also a way to do it with emm rgb values, which is how some ppl have "dif colored tattoos" and alike...check mira's clothes on how the symbol of infinity is used there and u will see what i mean by making a circle model

the mira symbol that u see in this emb, if u open the fbx for the bust, u will see that this symbol is a physical element in the game, so its not just a "green sticker" on the bust...which is what you need, but i think it can also be done with alphas...for example lets say u are using a white bust, idk white t-shirt...u map the uw to that shirt and then add the dds in the emb which is opposite on alpha channel, that way the black part of the symbol needs 2 be white in the dds, and whats white needs 2 be black...the black part will become transparat, and the white part will become black colored, and with ur white bust, u will effectivly get half of yin-yang ( u will see that whatever u colored white in the dds alpha, will be black, as a sticker, so if you want to have a complete yin-yang, you need 2 also have an outline for the rest of the symbol, so from ur pic of yin-yang= the outline needs 2 be white, the black part needs 2 be white, when u put it in game u will have a yin-yang as it is on the pic, assuming you are using a white shirt, if your shirt is idk red for example, then half of your yinyang will be red aswell....idk maybe in not as good at explaining sorry