For gold I use Rainbow Dust ivory shimmer adding yellow and brown gel colour with alcohol. (I even use the same ivory lustre dust for bronze or silver in the same way.) I do that because the ivory lustre dust is the only one we can commonly get as food approved in Japan. It doesn't look really metallic but I like it.
So, if you don't need very metallic shiny finish, I think you could grab light colour lustre dust and add some colours to get what you want.