First color photograph baseball card set?
 

I recently learned about the 1948 Signal Oil minor league set which used color photographs. Does anyone know of any earlier sets using color photographs of the players?

I do not know of any earlier than 1948 Signal. Yes, there are others colorized, but Signal was first with actual color photography I truly believe. And those Signal cards of the Casey Stengel-led Oakland Oaks with Cookie Lavagetto, Ernie Lombardi, Dario Lodigiani, Johnny Babich and Billy Martin are beautiful cards. I also like the broadcaster Bud Foster card, who as a civilian correspondent with the Marines in WW2 was wounded in combat! This is one of my very favorite sets of cards.

I knew both Dario and Babich.

Dario played on the same h.s. team as multiple DiMaggio brothers, including Joe. Imagine that.

Here are my 9 Signal Gasoline cards.

I have never heard of these before today but I really like the look of them. Kind of crazy that a relatively obscure set has two Hall-of-Famers plus Billy Martin and Cookie Lavagetto. Also crazy that Stengel was about to jump from the minors to his incredible run with the Yankees.