As for the diversity of this and the Samurai cast,they were the same diverse cast from Space. Megaforce’s exception is the Black Ranger is middle eastern instead of hispanic.
Fun fact: the Yellow Ranger was going to be black (she was going to be played by Sundai from Top Model season 13), but since they already had a black person, they didn’t need another, apparently having two black people is considered “too ethnic” for a kids show…