When the Denver & Rio Grande and Rio Grande Western railroads merged in 1908, the D&RG created a new universal identity for the companies' rolling stock. This decal set represents the D&RG's standard gauge 34-foot wood refrigerator cars. Letters one car.

The 31000-series refrigerator cars comprised 200 cars total, numbered 31000 through 31199. According to the 1909 lettering diagram that this artwork was traced from, they were painted "Acme Chrome Yellow" on the sides and Prince's Metallic (mineral red) on the ends and roof.