Did you know that in "Thanos doesn't know the Color of his own Nlood..."

Thanos doesn’t know the color of his own blood. So, during the fight between Thanos and Iron Man, when Tony makes Thanos bleed with his nanotech suit,we can see that his blood is red. I think this is the first time Thanos ever saw his blood because when Gamora stabs Thanos’s fake projection on the Planet of Nowhere, we can see that the blood there is purple. This suggests that Thanos didn’t know the color of his own blood and assumed it would be purple because of his skin color, or maybe it’s purple because of the Reality Stone.