Pulp writers in the 1930s and earlier (and some later) had a problem when writing some stories: The hero would occasionally need to disguise himself perfectly as a specific other person, but they couldn't say that the hero was wearing makeup, because that wasn't manly. Pulp heroines (of which a few did exist) could get away with having such brilliant makeup skills that they could appear to be a completely different person with just a wig, different clothes, and the contents of their purse, but male heroes had to also be paragons of era-appropriate manliness. Some used specially made rubber masks, others donned 'an actor's greasepaint' (which was a form of makeup, yes, but they didn't call it makeup, which apparently made all the difference to some pulp magazine editors - and anyway, you wouldn't call Lon Chaney or Clark Gable unmanly), but a few did something a lot stranger: Through training in the Mysterious Orient, they possessed the discipline to contort their facial muscles such that they appeared to be someone else (like the scientists the bad guys want to kidnap, or the thug he just knocked out and tied up). Superman, who had previously used the greasepaint dodge, demostrated the ability to 'contort his plastic features' in the 1940s, at one point, IIRC, making his face look like a stylised tribal idol (like a tiki mask, or something weirder). The most recent use I can think of was in a movie from 1987 called
Innerspace, where a guy in a miniaturized one-man submarine uses electric shocks to disguise a store clerk as a guy with a different complexion, build, and height (it was a comedy).
It seems to me that both versions would be Morph with something like the Cosmetic limitation, but limited to the face. For the more normal version, it would also be limited to humans with a similar complexion to the user, as while you could us it to make your skin paler or ruddier, actually becoming more or less tan would require either makeup, a different justification, or a Silly setting. The less normal version, as in Superman and Innerspace, would just be Face Only Cosmetic Morphing without any additional limitations (in fact, the Innerspace version might be Cosmetic Morph without Face Only, but in the movie the only thing he said he was changing was the face).
The question is, how big of a limitation on Morph is Face Only, and how much does 'Humans with similar complexion Only' add to it?