Vulcan skin coloration doesn’t appear to have any connection to the greeness of the blood. Lips are pink, for example and Savik’s cheeks didn’t burn green when the admiral noticed her new hair.
I haven’t seen the symptoms appear on Trek, and it’s a level of detail I’d only expect to see in a novel, but I don’t read much tie-in stuff. If I were writing Vulcan physiology, and I occasionally do for fun, I’d probably conclude that Vulcan blood is green when it’s oxygenated, so it’s probably copper coloured when it’s not.
My approach to Vulcans wouldn’t match much of what we see on screen though.
