Yellow is super helpful as well you just have to make sure that there is a big difference in the amount of tiles for whichever color you choose. Also the blue power will eliminate the attack strike and protection tiles that the enemy has on the field. Also adds a fortified tile/s to your invisibility or power up tiles
Today almost teared my hair trying with an underlevelled (280) Peggy against Wasp. Board was constantly either purple or green and all my attempts with blue was swiftly matched away. Got stinged and knocked about twice but third time board was in my favour and I won. The second match agains BP was won in a couple of matches. RNG. Peggy's blue is a bit stunted without allies and three enemies.