Now this is interesting. I noticed in the trailer still, Belloq's tie is quite blue, but so is the balance of the frame. In the other grades and regrades, the tie turns quite green. So I searched for how the tie is supposed to look, and came across this:
Here the tie is clearly gray, whereas the Nazi officer's tie remains quite green. Overall, Belloq's suit seems more balanced here. Just some more data to consider :)