Dyes Preview Bug
I have the same problem, I hope they will fix it soon.
I too have the same problem. I hadn’t noticed it was the currently chosen color, but from what happened to me and the OP’s screenshot (the head armor is barely visible) I did notice that it only happens on armor that can’t be hidden (chest, leg, and feet).
Came here just to post this very same thing, actually. Putting on and taking off an outfit fixed the preview window briefly, but when I closed and reopened it it was back to the monochrome look.
~Veteran~