^^^Looks more like the editor wasn't paying attention to costume continuity after they successfully went to warp.
Are you sure the continuity issues are due only to editing? The dialog uttered by Scotty
in the pic with the red rad suit
is pretty specific to that moment in the film.
SCOTT: Captain, if we don't break free in fifteen seconds, she'll burn up.
Of course, the next time we see him, he and other officers are back in their regulars, when discussing the self-destruct. You're right, that doesn't make much sense, though the order to prepare for self-destruct and the discussion in engineering that followed was cut from the theatrical release.