My apologies to Mel. I was writing in a hurry at the office.
A couple of points to remember. Although the flood wiped out the F&CC main line south of the district, narrow gauge rails and trains continued to run in the district until 1915. In the beginning they ran as F&CC and then later as the Cripple Creek and Colorado Springs (CC&CS RR). Very little equipment ever got repainted as from 1912 on, they were planning to remove the NG rails.
The gondola picture shows the cars as they were in the period that you are trying to model. 350 and 352 were some of the original cars painted yellow, with the black center panel and the gold belt herald. After more than 10 years of use, they were simply painted boxcar red and lettered with reporting marks and numbers.
The same goes for the box cars. Originally they were boxcar red, with the gold belt line herald (some had the herald in color, most in simply white). By 1910 many had been repainted simply with reporting marks and numbers.
Some of he former F&CC cars that ran on the Montana Southern that are at Virginia City MT, show both paint schemes, one on top of the other, as well as the MS initials. (at least that is the way that I remember them from 1967 but I will have to dig out my slides to substantiate this)
This is a long and round about way of saying that the reporting marks and numbers painted on boxcar red is correct for your time frame, but I am sure that there were also well worn cars painted in the original fancy color schemes still around even at the end.