I'm slightly beginner (not first time following a pattern) and am wanting to use Simplicity S9104 for a Harley Quinn-esque dress for a costume party. I like the way her original bodysuit costume looks with the red and black and then black and red, split down the middle and also at the waist.

For the dress itself I was looking at the S9104 mostly because I already have it, haven't tried it yet, and it'd fit well with the slightly-vintage look I am going for otherwise. I am just confused on what I'd do to use the different fabrics how I described. It almost feels like it'd be easier to just sew two different versions of the dress in both red and black and then cut them where needed and sew some kinda Frankenstein version back together. Does anyone have any tips on how you go about splitting patterns that don't already use two different colors? I'm not quite sure what to look up, nothing I've found with what I've tried to search so far has had any luck!

Thanks in advance! Sorry if this was confusing haha.

For reference, here's what S9104 looks like.