Gotta say, the uniforms certainly didn't slow the 1956 Angels down, as the team went 107-61, walking away with the pennant.
Nor did they slow down Steve Bilko, who had his PCL Triple Crown season. He led the league Hits, Walks, Runs, and Slugging, too. Bilko is seen here on August 27th, hitting his 50th HR of the season. (He struggled a bit down the stretch; he had 45 blasts by the end of July, but finished with only 55,)
Gene Mauch said that the Angels were better than some major league teams he managed. Given the epic losing streaks Mauch presided over with both the 1961 Phillies and the 1969 Expos, that's not too surprising an opinion for him to hold, I shouldn't think.