They actually look quite a bit like Team Rocket, what with the black uniforms and the red hair. I think it's a ploy by Ghetsis. Everyone knows what Team Plasma look like, so either he's gotten what members he could round up to dress as Team Rocket, or else he has employed the real (what's left of it) Team Rocket.
------------------- "I swear on the name of Dumuzid, the Shepherd, consort of Ishtar! Your ass is mine, punk!" - Thomas Mutton