Hey Charlie, I've seen your thread here and on Trainorders making this inquiry. I wish I had more information to give you, but when I was growing up in Ft. Collins, C&S used these wooden cabooses almost exclusively. I think some of them were painted very dark red, almost a maroon color. There are several around northern Colorado in various people's backyards. I'm pretty sure that the "Greeley Freight Depot" museum has one in these colors. This museum is just about a block south of the UP depot in Greeley and is under development.
Best,
Jim Burrill