I exported the list and created a small node app to sort the colors: https://github.com/dcustodio/colorcount
the top five is #00000 (66 occurrences), #CC0000 (18), #FF6600 (12), #FF0000 (10), #FFCC00 (8)
This is a really tool. I've always been meaning to create a list of all the works that use BrandColors or are derived from it. If I ever get around to doing that, I'll make sure to include this.