★ magenta's most defining feature (by far!) is the big-ass scar on the left side of his face--like in this specific icon. his eye is totally gone underneath it, but it's hard to tell. (there's also a matching scar on his chest, and a healing injury going through his foot.)
★ related to the above, he has a slight limp! he literally shot himself in the foot. (well, it's more complicated than that, but y'know.)
★ he's tall, skinny, and Looming. he wasn't an especially big guy to begin with, build-wise, but he's lost a lot of weight both in the weeks leading up to his current canonpoint and in norfinbury.
★ his remaining eye is drawn...inconsistently, but usually as a blue-purple-grey.
★ also, at this point, it's worth mentioning that he's drawn to specifically look like marc bolan, british glam rock star. because, you know, this is jojo's bizarre adventure, and everyone has to have that weird obligatory rock reference in them. the most noticeable bit of this influence is obv. magenta's lovely Mess Of Hair, which is dark, curly, and a pain to deal with.
★ for a jojo, he's weirdly presentable? his main outfit consists of a top hat + heavy coat + collar...thing w/ brooch + underclothes, all in shades of...well, magenta. he has an aesthetic to maintain.
★ magenta sounds AWFUL. canonically. he doesn't have any actual in-game voice i can reference, but the way his dialogue is written indicates that he's...well, if you want to go by the translation team's approximation, he sounds like "a more coherent donald duck", with a side of very rural-sounding charm. this is halfway natural, halfway because he's Always Sick and sneezy.
★ oh yeah, he's Always Sick and sneezy. he drools a lot as well, because TBI. he's mad about it.

★ as mentioned above, he's skeeny as hell, and shakes a lot. he doesn't deal well with cold.
★ most of the time, he keeps his hair tied back with hairties, for practicality. it makes him look kind of goofy, but he'll defend his fashion choices to the bitter end.
★ when out and about, he also tries to keep some fabric over the scar on his face in a makeshift eyepatch. (doctor's orders.)
★ since he's not even SEEN a razor since arriving in snowhell, he has a fair amount of stubble going on. more than stubble, really, though a far cry from an actual beard.