Although I had no idea when I started building this droid, there was actually a Red R2 unit seen in the original trilogy. Specifically, there was a red droid just like mine in The Empire Strikes Back. Thanks to an excellent fan site, we now have very clear evidence of this "blink-and-you-miss-it" background droid.
Notice that in the back of Rebel base is a red and white R2 unit. Thanks to some new pictures I hadn't seen until recently, the photos are much more clear.
If you are keeping count, that means that a Red R2 unit was seen in The Phantom Menace and The Empire Strikes Back. A digital version was also seen in a naboo fighter in Attack of the Clones. That quite possibly means that this version of an R2 is the most-used droid outside of R2-D2!
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