The indian red SF cabooses had Shock Control equipment, thus the same color as the Shock Control freight cars.
The mineral brown cabooses had no cushion equipment.
This happened with the "Ce" rebuilds which were done in the 1960s.
Here is a great link that explains the Ce-1 (first class of rebuilds). They started in 1966:
Santa Fe Ce-1
Matt from Anaheim, CA and Bayfield, COClick Here for my model train photo website
The change appears to have been made by 1970, although many cars remained in the older Mineral Brown color after that date. Hopefully some AT&SF fan can give you a more solid, reliable date.
What year did Santa Fe repainted their mineral brown cabooses into their classic Indian Red paint scheme with the huge yellow ATSF Herald with the yellow stripe? Any information will help.
Amtrak America, 1971-Present.