If I remember correctly. I went left and was presented with the white boss. So i tried to change to black and shoot it so i can damage it. The thing is, i would switch to white after a second. So i had to keep tapping switch so i turn black to do dmg. Against the black boss i could switch to white and just keep attacking. Against the white boss i was not able to keep my black state. Again, if i remember right. I'm quite sure this was near enough what happened though. I would have wanted to be in the opposite colour state so I can dmg but the game would just switch me back to the other colour after a second or so.