The choice of paint depended a lot on the enduser nation. The law since 1942 has been that any military aircraft built in the U.S. have a paint scheme that is covered by Department Of Defense Technical Order. The overall gray scheme was standard in several Air Force Commands at the time (in particular, Air Defense Command and Training Command) and was applied to Air Force T-38s. The enduser nations could choose this and some did, others chose the Temperate Tactical Scheme (Taiwan, for one example) or the Asia Minor Scheme (Jordan, Iran, Saudi Arabia).Does anyone have any idea why various models of F-5 fighters [A, B, F, and E] were delivered in a single grey colour scheme to various countries in the 60's and 70's? Was the grey colour scheme intended to make the aircraft hard to spot from a distance or was it due to another reason?