According to the Hall of Fame website's "Dressed to the Nines" pages, as researched by the late Mark Okkonen,
Red Sox road unis were essentially unchanged during the Babe's tenure there. The one slight subtle difference
might maybe perhaps be that their road caps appear to have been the same grey as the rest of their unis
in 1915 and '16, but distinctly paler than the rest of the uni from 1917 through '19, as in the photo in question.
Or maybe it's a trick of the pixels...
http://exhibits.baseballhalloffame.o...ar&increment=9