What color is our (human) blood when it isn't oxygenated? I thought it was still red, just duller.

But if that is the case, I bet Vulcan blood would continue to be greenish-blue, just duller.

I could be speaking out of my rear though. All the wiki's I browsed (I'm bored at work) did not mention oxygenated blood vs. un-oxygenated blood. :/