The thing with R's design is that he's very canonically ugly, but I can't see "ugly".¹ I just never feel repulsion when looking at human traits. It's not a political stance but an instinctual lack of reaction. Lacking a internal compass telling me who is ugly, I can just use conventional ugly traits but those imho are associated with poverty, illness, violation of gender roles, violation of North European traditional aesthetics, old age². So even if I give R random conventionally ugly traits, I still won't think of him as ugly but as something else. It's a fruitless effort. So I gave up on picturing him as ugly and physically repulsive to me.
-something makes him repulsive, but it's nothing people can explain rationally. No ugly trait in particular. After all, he's described as "impossibly" ugly. What if it's impossibly ugly because people can't say why he's looks ugly to them? Because it's a sensation that defies logic? My realistic headcanon is that people can sense his all-encompassing dread and lack of any positive belief, and they fear it and from fear it comes the irrational repulsion, also I'm sure that his behaviour toward women has a big impact on his perceived ugliness. It would be right in Hugo's alley anyway, Hugo uses ugliness as a visual metaphor for psychological and social issues.
(In a fantasy!AU I like to headcanon his perceived impossible ugliness as people unconsciously feeling that he's not human. The same is valid for Enjolras, but with his angelic and statuesque beauty.)
-I adopted as headcanon what it can be deduced from the brick. He's 26-29 years old, so quite young, he's fit and strong because of the multiple sports he does, he's short because he's impressed at Enjolras's height, he must have good hair because he appears to be proud of his hair and glad of not going bald like Bossuet. He's supposed to be the apparent opposite of Enjolras, so my headcanons are dark hair, small forehead, bad teeth, strong manly features. His hair may have been ginger too because Hugo had a bit of anti ginger bigotry and he stupidly thought ginger hair were ugly so he may have thought of R as red haired when he wrote he was ugly. Ginger!R is a fascinating idea to me, 99% of the times I see him as black haired, but I think ginger hair is a likely feature for brick!R (and also hot NGL).
-Bladgen!R has imprinted on me, so I borrow some of his features, but he looks too delicate to be R, so I usually roughen up his face a bit when I think about him as Grantaire. He's also too beautiful (I can tell when someone is beautiful to me), but when I try to think of traits to assign to R to turn him ugly, my mind goes blank. Without the obligation to make him ugly, I manage to picture him with different features, but I can't give up on his curly hair in the 2012 movie. Grantaire with curly hair is fixed in my imagination as if it was canon. Bbc!R is sometimes R in my mind, but I don't think he's ugly either (on the contrary, I find him beautiful as well), he just gave a great R impression thanks to his interpretation. No musical actor left something into my headcanons, it's regrettable because I usually enjoy a lot musical!Grantaires.
-Canon R is white imho, he talk about other ethnicities as "other". I'm not sure because he may identify with the dominang group despite not being part of it, but it's a likely guess. He also said he would rather be born a Turk/Arab, he's was joking/trolling, but I take it as inspiration for modern and reincarnation AUs. Obviously, it's unrelated with his perceived ugliness, and to avoid involuntary correlation and involuntary endorsement to white supremacist propaganda, I would explore his ugliness and being Arabic in different fanworks.
-Green eyes just because he's associated with green by the musical.
-Damages from his addictions. So corrupted teeth from smoking and alcohol, flawed skin from smoking, sleepy/tired eyes. Those could work as conventionally ugly traits, but I still think of them as neutral, bad just because they're symptoms of bad habits, not necessarily bad to look at.
¹I'm not trying to be holier than thou, I acknowledge ugliness is real and can be defined by what triggers repulsion at the sight. I can feel this repulsion when I look at very ugly architecture, for example, but I simply don't feel it when I look at people. If I'm repulsed at someone, it's just because I already hate them because of their behaviour. I don't know if it's related, but I don't feel repulsion at anything from the human body either. I've spent some nights in the hospital with surgery patients, and nothing repulsed me, no fluid or matter I saw. It's not high morals, it's high scientific interest, and the human body is too interesting to me to feel other than utter fascination. Like there is one thing I find ugly, and there are bushy eyebrows. idk why, that's it. As I said, lacking an internal compass that tells me what's ugly to me, when I try to picture ugly, I resort to conventions. ²But "ugly" traits are always ugly for ulterior motives, they're ugly because they're associated or they have been associated in the past with the poors (es badly groomed hair, inelegance, bad teeth), they're associated with a lack of health and physical strength (fat bodies, very skinny bodies, asymmetry, paleness, eyebags etc), they defy gender roles (moustaches/beard/big bodies for women, small stature/small hands/small D for men), they're typical of old age or they're anything else than north-European (big noses, bushy eyebrows too probably). I don't blame who find those traits ugly, we can't choose what is repulsive to us, we can only treat everyone decently (unless they're being harmful). But while I recognise ugliness is legit, I see every ugly trait as being something else, the trait of a poor/sick/old/androgynous/poc person so I'm unable to think of someone who is just objectively ugly. Instead I can well see beauty, I'm charmed by people with some colour and proportions as if they were work of art, also I see beauty in all the people I care about because looking at them is pleasurable to me. The opposite of beautiful is just "normal" to me, when I don't feel anything when I look at someone, likely with random strangers.
