The Mets did not score after the second inning all weekend. They struck out 15 times on Saturday and 13 more on Sunday.
The Mets took a quick 3-0 lead when Curtis Granderson drew a bases-loaded walk and Daniel Murphy hit a two-run single in the second inning.
"It was a good road trip," general manager Sandy Alderson said. "It could have been a great road trip, but this team played us very well. They've got a good club. We're happy to be 4-2 and are looking forward to the homestand."
This was the second straight loss were they failed to protect a three run lead. Colon gave up a tiebreaking solo home run to Richie Shaffer in the bottom of the seventh.
The Mets dropped to 59-52. The Nationals lost to the Rockies, so the Mets are 1.5 games up with the Rockies coming to town.