Lockheed in their wisdom offered 3 choices for cockpit colour schemes on the L1011 - grey, blue or olive green. My past employer bought some new Trimotors with grey, some used with blue, and got into a parts pool with an operator with olive green so we had some interesting combo's as seats and things got moved about. Fortunately the colour variations were only in the background trim and actual instrument panel structure and the actual radio tuning heads, instruments, etc were all grey if I recall correctly.