I've added additional colors to this mod, so it doesn't break if you chose anything different from color 1 and 2.
The first five colors are for the costume without helmet, and from 6 to 10 the same 5 colors with helmet.
Four initial colors are red, blue, green and yellow arms stripes with black armor. The fifith color is a navy blue armor with yellow and white arm stripes, similar to the color scheme I use in Mass Effect 2 and 3 games.

Mod is set up to work on costume 1, and I haven't tried it in any other slot, so no idea if it will work.
If you want to try in a different slot, be aware you got to rename the files.

Drop the contents of the zip file inside your game folder at:
...\Steam\steamapps\common\Super Street Fighter IV - Arcade Edition\patch_ae2_tu1\battle\chara\PSN

If this folder doesn't exist, just create it.

The mod shouldn't overwrite any file, but make sure to have a backup of your original files before installing the mod.

Original mod:
https://www.deviantart.com/xheczx/art/USF4-Sheppard-x-Poison-504659475