When I watched the season finale of season 3 of Star Trek: Discovery, during the final season on the bridge, Tilly is in sciences blue. If you look at the screenshot on this page: (you'll need to scroll down).
Tilly is in command red. In the latter part of that scene when they pan by the bridge crew, when paused the science blue of Tilly's uniform looks as if it was photoshopped in. Has there been anything to indicate which division she's actually meant to be in (command red or sciences blue)?
It makes me wonder if they decided right at the very last minuet to change what division she's in (plus also you can't see the whole of her comm badge so there's no way to tell if she's been promoted).