To which "Well, that color/style/fit/whatever doesn't particularly flatter you. Shall we look for something else?" is an acceptable response in any relationship I'm willing to care much about preserving, all else being equal.

But, sure, one can easily imagine situations in which all else is not equal. (Which is to say, I don't share the OP's view.)

Tangentially: someone asked me roughly that question once, somewhat tongue-in-cheek. I replied, roughly, "Hypothetically speaking, given a choice, would you rather have evidence that a friend of yours was willing to answer questions honestly even when the honest answer incurred a potentially high social cost, or would you rather have evidence that your friend was willing to conceal an unpleasant truth so as to spare your feelings?" They thought about it for a bit and somewhat hesitantly chose the former, and I told them they looked lovely (which they did). That left them puzzled for quite a while.