Here's another look at it:
Basically, the changes are these:
-No breifs
-All black (or simply darker grey, depending on the colourist)
-The gloves and boots are part of the bodysuit, instead of being seperate
-The boots have fins on them.
However, the costume was rendered inconsistently. Some artists would draw the gloves and boots as being separate from the bodysuit, and some colourists would colour the bodysuit grey. Worst of all, even though the costume was supposed to be all black, the cape and cowl were always coloured a blue-ish black, where the bodysuit was always coloured greyish black. Accordingly, the suit still looked two-toned.
I maintain that an all black suit would look fine if they would actually colour it consistently black: one tone, with no difference between the cape/cowl and the rest of the suit. That said, making the suit all black is not necessary.