Perplexing Doppelganger

Chromatic (This creature's color identity is decided by whichever color has the highest
number of permanents on the battlefield.)
If Perplexing Doppelganger is blue, it has
"{u}{u}, {t}: Target player draws two cards."
If Perplexing Doppelganger is black, it has
"{b}{b}, {ut}: Target player discards two cards."