Painting

 To paint R2, I used off the shelf cans of spray paint. 

For the white parts, and as a primer for all the other parts I used Rust-oleum Ultracover Paint+Primer Flat White.

For the silver parts I use Dupli-Color Chrome High Gloss. 

The trickiest color is the blue since it's hard to get a good sense of what the correct color is due to different paint jobs and lighting conditions in the movies. I ended up going with Dupli-Color Sonic Blue Pearl.

The Dupli-Color paints are automotive paint and can be found in auto-parts stores. The tricky part with these is that they are very sensitive to humidity. If it's to humid you will get cracking as the paint dries. I ended up doing most of the painting with these during the winter when the humidity was lower.