Did you look at the various episodes? Also, look for the Japanese footage as well, they should have some shots that never made it to the US version. Don't forget, the show we know as the Power Rangers started in Japan, so a very large chunk of the morphed combat sequences are all ready not new...
There might be some good ref pics in the Back in Black episode. I don't recall the backs being much more than a blank, solid color...but I could be wrong.