In addition to allowing two touchdown passes, Colvin allowed wide receiver Ted Ginn Jr. to make a last-second catch, which set up the game-winning 58-yard field goal by Saints kicker Wil Lutz.
Colvin spent the first four seasons of his NFL career with the Jacksonville Jaguars before signing a four-year, $34 million deal with the Texans last year.
The 27-year-old Colvin started two of the 10 games he appeared in last season, finishing with 29 tackles, one pass defended and no interceptions. Colvin has never intercepted a pass in 59 regular-season NFL games, although he does have one playoff interception to his credit.
Colvin, who was a fourth-round draft pick out of Oklahoma in 2014, enjoyed his best season in 2015 when he registered 73 tackles and seven pass breakups in 15 starts for the Jags.
With Colvin out of the picture, Keion Crossen, Phillip Gaines, rookie second-round pick Lonnie Johnson Jr. and rookie sixth-round pick Xavier Crawford are in line to provide depth behind starting corners Johnathan Joseph and Bradley Roby in Houston.
In Washington, Colvin will compete for playing time with Dominique Rodgers-Cromartie, Fabian Moreau and rookie seventh-round pick Jimmy Moreland behind starters Josh Norman and Quinton Dunbar.
The Redskins were torched by Philadelphia Eagles quarterback Carson Wentz in Week 1, as he threw for 313 yards and three touchdowns, including a pair of 50-plus-yarders to wide receiver DeSean Jackson.
In Week 2, Washington will host the NFC East rival Dallas Cowboys.