Painting the panels will bring your R2D2 dome to life. This three coat system gives them a grade shade of dark blue. I painted all panels with a purple lacquer paint from testors.
I did a couple of coats but perhaps one light coat may work better. I would have to build another dome to find out.
I waited 15 minutes and painted on a wet coat of Blue anodized duplicor that I got from the autoparts store. I painted two coats of this 15 minutes apart. You can tell it really turned the purple into blue.
After the two coats of duplicolor was applied, three coats of Rustoleum Crystal Clear Enamel was applied 15 minutes apart. This really brings out the blue in the panels and makes them shine.