I’ve been watching a lot of Star Trek lately. While the green blood jokes were common on TOS between McCoy and Spock, were there any other references to this in the subsequent TV series or the films? I can’t remember any, but I’m more of a casual fan.
I’m pretty sure McCoy made a green blooded joke in Star Trek IV.
In the last of the three J.J. Abrams reboot films (Star Trek: Beyond), Spock (then played by Zachary Quinto) is critically injured when crash-landing on a planet, and Bones has to do some emergency first aid on him.
I can’t find a good/clear picture of it, but I’m pretty sure that Spock’s green blood was shown, as part of his injury.
In “Wrath of Khan,” McCoy calls Spock- he’s not joking at all - an “inhuman, green-blooded…” before he’s cut off.
An episode of ENTERPRISE (“The Forge”) has Captain Archer being shown around Vulcan: “Some say Surak crossed this expanse when the hot blood of battle still flowed green; but, with logic, he cooled it.”
Here’s a screenshot of Tuvok (from Voyager), with green blood flowing from his nose:
In III, of course, he finds out he’s been carrying Spock’s katra all this time: “That green-blooded son of a bitch! It’s his revenge for all the arguments he lost.”
That’s the one I was remembering.
I seem to remember Spock being shown bleeding green blood when injured in Strange New Worlds, as well.
I don’t know if the Star Trek novels are considered canon, but in one of the novels it was explained that in Vulcan physiology, the blood uses copper as it’s oxygen carrying medium (as opposed to iron in humans), which is what makes it green.
I bet the horseshoe crabs of Earth will be surprised at this news.
I think ST:VI had Vulcans bleeding green and Klingons/Romulans bleeding pink – all in zero gravity, IIRC.
Klingons, yes; my understanding is that they gave Klingons pink blood in that movie, in order to keep it at a PG rating, rather than PG-13, which the film likely would have gotten for that scene, had it been human-looking blood.
In the first of the JJ Abrams films, Bones gets to deliver the “Are you out of your Vulcan mind?” line before calling Spock a ‘green-blooded hobgoblin.’
(“…my GOD, man; you could at least ACT like it was a hard decision.”)
It’s been forever since I’ve seen ST:VI, but I thought Kim Cattrall’s character killed some fellow Vulcans near the beginning of the film and there was green blood on the corpses. 
Quite possibly; I haven’t seen it in 30 years, either. I was mostly clarifying that the pink blood was from Klingons, not Romulans, in that film.
You realize that if they had portrayed Spock with red blood, every Trekker in the world would have called them on it immediately. 
…every red-blooded Trekker, surely?
(“Spock, that green blood of yours may have saved you before, but this time it almost did you in.” - ST:TAS, The Pirates Of Orion.)
In one episode of TOS, Spock (or maybe Sarek) said “My hemoglobin is based on copper, not iron.”
Spock was shown bleeding green blood in more than one episode, and in “Journey to Babel” the transfuser unit in Sick Bay was clearly pumping green blood.
Having green blood saved Spock at least three times (“The Man Trap,” “Obsession,” and “The Apple”).
Are we sure that’s not just everyday normal green Vulcan snot?
“Snott here, Mr. Schlock.”
“What’s not there, Lieutenant Snott?”
“I said, ‘Snott here, Mr. Schlock!’”