I use two colors to separate subsonic vs supersonic, and have settled on just two powder colors (after testing a lot of them) for their different attributes. Every powder I've tried works a little differently, some are slicker, some are tougher, some stick the bullets together too hard, etc.
My subsonic powder is a cobalt blue that is not tough enough for high pressure loads, but is very slick, and the bullets break apart easily without leaving bare spots.
My supersonic powder is a yellow/green that is very tough and slick, and doesn't stick bullets together as badly as some others.
The candy colors have been the worst for sticking bullets together, and being a little grabby in the bore.
