The character would need to be shown as being an antagonist character in this exact version as step 1, and then cohesive references showing all 360° of details would need to be gathered before it could be given the green light of acceptability.
It's kind of rough with switcheroo characters like this because certain versions are approvable, and certain ones are not. Examples would be Anakin with short hair being Rebel only and long hair scar version being both, or black suit Mara being 501st only and her green outfit being Rebel.
The simplest way to decide is, "did the character act as the antagonist in the story by actively working against the, 'good guy' while wearing this outfit?"
If that can be answered with a, "yes", then gather the 360° references and we move to step 3 of your build process.