1903 through 1906 appeared to have the same uniforms. The only change noticed is the emblem on the cap, which was a new design that also incorporated a T in the emblem, reading STL. We also saw this emblem used on team overcoat jackets.
In 1904 the National League officially mandated in the rule book that white uniforms would be worn at home games, while gray uniforms would be worn on the road. In this era, we also see photographs of the entire team wearing jackets with STL emblems on them. Sometimes this emblem matched the emblem on the cap, and sometimes it didn’t.
Newspaper Accounts
St. Louis Post Dispatch: April 5, 1903
Capt Donovan’s men were glad. They had every reason to be. They had the prettiest new spring suits of bluish gray, trimmed with red and new caps with white monograms.
Team Colors
Cardinals red – PMS 200
Cardinals Uniforms & Logos 
Fantastic site – referred via Uniwatch. My cousin Dave Zearfoss played on the club in 1904 and 1905. It appears he is the player featured in the photo next to the 1904 jacket… do you know where this display is located? thanks!
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i believe it might be apart of the Cardinals collection, and could be on display at their museum in ballpark village.
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