Hm.. This looks tough. Blue needs X people without the blue win-con to die.
At a minimum, we need 5 Yellow win-cons and 4 Red win-cons alive, with the constraint that #Red < #Yellow. Blue also needs to be less than Yellow, but that may end up being satisfied just because we lynched a pure Blue yesterday.
Blue needs to kill X pure Yellow or pure Red, or Red/Yellow (Orange) hybrids. But Orange hybrids help satisfy both Red and Yellow win-cons, so we don't want to kill them.
Best chance is to kill all the pure Reds and let the Red/Blue or Red/Yellow satisfy Red's win-con. There needs to be an extra pure Yellow or Yellow/Blue (while still having less Blues) to satisfy Yellow. There probably isn't a lot of pure Reds though.
Also keep in mind we can only kill one player a day. There is only 3 left. Hmm.. that seems to make it not possible if X > 3 (which I think it is). So for this to work there has to be a night-kill mechanism. If it works the way I think where R+Y+B = Black = die, and Black retains all three win-cons, it's not possible as Black deaths won't count towards Blue win-con.
Any thoughts on different Black mechanics? Does anyone have the ability to STRIP colors from people?
Mod: If I'm dead at the end of the game but my win-cons are still satisfied, do I still "win"?