Here’s an update of the color grading to more accurately represent the blue panels of R2-D2, which were too purple in the previous iteration:
From what I’ve seen of the behind the scenes stuff, photos of the R2 props, and from the R2 builders club, R2 is supposed to be the slightly purple blue that you have just removed. Everything I’ve found says that the panels had a more purple tint in the original movie than they did in the later movies.
http://www.robotbuilders.net/r2/FAQ/r2_compleat_faq_v12.htm#_Toc11840561
Mike V, who probably knows more about the original R2-D2 also has the purple tint in his model, so purple it is.
Thanks for the heads up!