The 44-year-old Colon has struck out seven and thrown 83 pitches, 59 for strikes. He went to an 0-2 count against 10 of the first 18 batters he faced.
The beefy Colon, a fan favorite all around the majors, is on his ninth team in the last 11 seasons.
Texas leads 1-0 on a home run by Robinson Chirinos off Astros ace Justin Verlander in the third, the only hit of the game. Verlander has fanned nine through seven innings.