Using Strategy in Card Collection. A player should try to gather cards of different colors, like a blue or green 5, in order to form a colorful run, for instance, if they have a red rummy list 20235, 6, and 7 in their hand. Players should endeavor to gather cards of various hues when assembling building sets so as to produce an array of eye-catching combinations. To create a colorful set, a player should attempt to gather an 8 of a different color, such as blue or green, if they currently hold two black 8s and a red 8. Monitoring the Moves of Opponents.