I’m sorry to disagree, perhaps I don’t understand but R2 looks blue to me, at least in this shot.
For those that are wondering, the bootleg williarob posted is actually a pretty good color reference. It’s colors are very vibrant, and there are a few surprises:
Green corridor, but no blue R2-D2.
I’m not talking about R2’s blue panels, but the fact that some of the print scans show this shot having a strong blue cast.