Only four models of the Air Force jacket are blue, they are N2A, N3A, L2, B-15C. The B-15C(MOD) version replaces the wool collar with a ribbing one, it is made from a custom-made fabric that authentically replicates the true color and characteristics of the highly durable nylon material from that era.
Nylon 66 was invented by DuPont Co. Nylon 66 is more flame resistant and durable compared to other nylon fibers. Bronson has studied the original Mil-Spec formula to replicate its yarn, density and weave.
Both O. D. and blue B-15C Flight Jackets became icons of the Korean air war, and possibly the most famous of the B-15 Flight Jacket series, having been extensively photographed while being worn by film star Marilyn Monroe and her entourage while performing in a USO tour of air bases just after the Korean war.