If her name's the Blue Lady so her shirt should be blue not white, that big white space just attracts the eye and becomes the most important color overshadowing the blue.
The Iron Skull... I know you didn't design the original costume, but I've long considered this to one of the ugliest superhero costumes ever. Your update is okay as updates go, but I wonder if maybe going back to his earlier suit and tie look might not work.
The Dark King, Black Whip and Magic Maker are all pretty darkly colored costumes. The first two kind of have to be dark because of their names so maybe consider some lighter colors for Magic Maker. I seem to think he was a nature-based magician, so maybe consider some nature symbolic colors like green (grass), brown (earth), blue (water/sky)?