This was really fun to draw. Catwoman has had a lot of varied styles in her history, with some styles being radically different than the others. It helped keep the drawing from just being the same thing over and over again.
I love it, well done
3 of them are cool and three of them ( latest 3 ) are "what was she thinking" !!!
The green costume was done to be like the 1960's Batman TV series. However, probably due to coloring restrictions at the time, a green costume is easier to have stand out on the page than a black costume.
The blue and red costume was done probably to give her more of an athletic appearance, to highlight her acrobatic nature. It may not exactly say "Cat" but it does give the appearance of being easier to move in than a costume with a cape and a skirt.
The purple costume with the cape is simply the one used as a standard "supervillain" outfit. It says "Cat" and it's colors contrast Batman and Robin's well enough. It's not surprising that it was the one the most commonly used after the other outfits.
I do agree her more modern costumes do play into the notion of her being a "cat burglar" one better than her previous outfits. But her previous outfits were more designed for her to be a standard supervillain, and did reflect the times they were made in.
I mostly used the drawings that Alan Davis did for "Justice League: The Nail" in a brief sequence as inspiration. Which is why the 70's Catwoman has longer hair than the bob cut that she had in the comics. Or the 60's Catwoman has a different mask and more of a plunging neckline.