The Galaxy ran its unbeaten streak to five games and for their third straight outing won by a 2-0 score.
Los Angeles (14-11-4) moved into a tie with Real Salt Lake for third place in the Western Conference.
Colorado (9-18-2) had been trying to win back-to-back games for the first time since the Rapids captured their first two appearances of the season.
Keane scored in the 15th minute, his 12th goal of the campaign. Wilhelmsson's goal came in the 59th minute.