I know lately the colors/styles for the line of swimsuits have been rather exotic (Save for that red one, reowr) but the last 2 years have had brown color dominating the look. In terms of fashion, these colors I think should get used.

Black
White
Green

Something simplistic is probably the best course of action for the swimsuits, I like the trunks on a hume male, but the blue one (Part of the +1 set that teleports you to Purgonorgo Isle) just drew way too much attention to it. I think it should be akin to a simple pair of black swimming trunks, and the top be something like a black shirt, something you see surfers wearing but the pants are loose and the shirt is essentially a black wetshirt.

On the other end of our gender spectrum, I think they should get a little more exotic in their fashion. For instance: I love the ideas of the skirts, it offers modesty and whatnot so it's good to keep. But perhaps a strapless bikini top is in order. I know it's odd to contradict the modesty of the skirt with the strapless top, but it'd be a step into another new direction. I think SE has used the tankini-style a little too much, and actually needs to make this a bikini where you can actually know that a female has shoulders.

My current favorite combination is the following.

Shoal Mallot
Marine shorts.

It's a sexy style for the summer, but I think either black or white should be the next color flavor.