When Goku and Piccolo fight Radditz, Piccolo's arm gets blasted off. When that has happened, you can see Piccolo's blood dripping from his arm. The blood is GREEN here. When Piccolo gets shot by Frieza, his blood is PURPLE.
Well, Piccolo's (and any other Namek-Seijin's) blood actually is purple. In the episode with Raditsu FUNimation removed all of the "real" blood or tried to make the blood look as little like blood as possible. Apparently purple blood looks too much like normal red blood so FUNi just made it green.
Actually, whenever a Namekian (or even Cell) regenerates, the "blood" appears green. And when a Namekian (and once again even Cell) is cut or hole poked through them the "blood" is purple. I figure that the green "blood" is excess regenerative tissue and the purple is the actual blood. That's just a guess but sounds reasonable to me.
I cant be leave that someone is actually offended by them changing the color of the blood, just because it is somehow censorship. I don't think that it ruined anything, and I for one consider myself better of NOT having seen Goku's butt.