Harmy said:

Well, what I'm seeing is that in GOUT the blue is overall of more purple tone (on R2, the pod and the sky) which I think is caused by the red shift of GOUT.

Harmy, did you end up doing any more tweaking to the overly-blue R2 in the desert scenes?

While I agree the red shift of the GOUT was probably dulling some blues, the particular shot in the desert has obviously been boosted beyond typical color adjustment. It has the same kind of glowing blue that we see when R2 is in space. R2 is not supposed to be that blue.

Interesting tidbit: An original R2 was used in the "George Lucas Super Live Adventure" in Japan in 1993. I remember reading that people were constantly asking why R2 was black. Of course he wasn't black, but his original dark blue came across as black under certain lights. So to solve the problem of the original R2 not looking right, they painted him blue!