"Desert Tan" is a color Fender appears to have matched to two Chrysler colors of the period. It was first seen on the 1955 Musicmaster; a student model which had a 22.5 inch scale neck. In 1956 Fender introduced a double pickup version, the Duo Sonic. The Duo Sonic like the Musicmaster was originally available only in "Desert Tan". From 1955 into 1958 the color used was the 1955 Chrysler color; "Desert Sand", Duco color #2121. After 1958 the color, while still called "Desert Tan", was changed to the Chrysler color; "Mesa Tan", Duco color #2857.
"Desert Sand" is a whitish color with a slight green tint. "Mesa Tan" is a medium tan color. ("Buckskin" would be a good description). The Chrysler color; "Mesa Tan" was the color used by Fender on the Musicmaster/Duo Sonic guitars from 1959 forward. The Guitar ReRanch colors, "Desert Tan '59" and "Desert Tan '55" were matched to my 1956 and 1959 original Musicmasters.