Barnes got control of Tally Hall's goal kick, dribbled downfield and unleashed a hard shot from a sharp angle that got past Rapids goalkeeper Clinton Irwin.
The result gave the Dynamo (4-2-2) an MLS-record 30-game home unbeaten streak -- 36 counting non-league games.
Drew Moor scored in the first half for Colorado (2-4-3).
Notable deaths of 2014 [PHOTOS]
UPI horse racing weekend preview