I bet that it would be green like the lore says and not like int he book where they say its red but that's just my thought, what blood color do you think would sute the orks or does every ork should have different colored blood?
Also blood for the blood god. Just to throw that in ther

Crimson, I remember reading a section in 'flight of the eisenstein' where ork blood is described as crimson

*Edit- it is simply described as red when they are debating what colour the jorgall blood will be "I'll say red, like the orks"

well they are fungus basically and i cant imagine why plants would have red blood but i guess I'm thinking way to much into it

They arn't entirely fungus, they have fungal strains in their genes. You could also say "I can't imagine why plants would talk and shoot thing" but this is 40k, shit happens.

Aye it's red, mainly as GW folks admitted themselves, green would look rubbish, so for an aesthetic point of view regardless of if it should be or not, it is red.

they are fungus/animal simbiote.
and fungus don't have clorophilla

I paint my orks with red blood. I just can't see putting darker green on them to show off their blood. Red just seems to pop out more, especially on their green skin.

Yeah. It's been red in most games for reasons already explained. And the chapter has extensive experience that green blood looks rubbish. So we've initiated exterminatus on those gene types.

.. Wait, this isn't the Space Marine sub section. Whoops.

I always imagined their blood as black even though every other depiction shows their blood as red.