You asked what the post popular colors are/were. Popular = most ordered/produced. I believe I heard that Twilight Blue was one of the most popular.
The first 100 Sigs could choose a special British racing green and it was the most popular of that group.
At the time, the picture(s) of Racing Green on Tesla's website were not very attractive. I suspect that the poor pictures discouraged some people. It is actually a pretty color.Racing green (not sure if the same as special British) and Fusion red were the two base model colors that didn't require an additional charge when I ordered my Roadster. I imagine racing green was fairly popular but I don't see very many.
My wife's Roadster (#40) is a Signature Green. It's darker than British Racing Green and looks like black on certain light.