Col is one of three basic placement games on graphs along with Snort and Node Kayles .  In all three, players take turns painting vertices their color, with a restriction based on what colors are neighboring.  In Col, you can't paint a vertex adjacent to another vertex that already has your color.  In Snort, you can't paint adjacent to a vertex in your opponent's color.  In Node Kayles, you can't paint adjacent to either color.  (That's not usually how Node Kayles is described, but this is equiv