I have mixed dwarfs before -- Coral Beauty and Venustus and then a Potter's and Multicolored both worked great. I currently have a Potter's in one tank, and a Flame in another, and even though I have to tanks if it didn't work out, I am not going to try it -- colors are too similar. Lastly (( and this could be just my fish )), my Potter's and Flame are way too headstrong to try to mix.