If you do dark red for Youbirin… is that not too close to Sakura’s pink and red ensemble? I mean the “canon Youbirin” which Silver Queen based the characters on was admittedly dorky looking but if you want to salvage his turquoise and orange vibe? Or maybe not orange since that’s Naruto’s color… but turquoise? Or… hm… that’s still a little close to the blue, isn’t it?
I mean… what you could do is what’s the spirit behind Rin’s outift. It’s dark colors, mostly, except for the white skirt/apron thing. Well… maybe the apron thing is supposed to act as scrubs? Like how surgeons wear green to contrast with blood… Like the Nohara clan aren’t combat strong, they wear dark colors so they won’t be noticed in battle, but they’ll wear white if it makes them better healers even if that puts them at risk.
So maybe it’s be best to go with dark purple and blue for him, with a white something. Probably not a full on lab coat like with the Medic Corps uniform SQ made for Sakura in this picture but still something that shows the Nohara sensibility to be medics before combat shinobi.