I only ever saw black cockpits on the Chippie (mid 70s to retirement) but developing the yellowy green primer angle, I was on camp at St Athan (Summer 79 I think) and saw one of Ark Royal's de-navalised Phantoms being air tested in an all over yellow/green primer. At the time all of the Ark's fixed wing a/c seemed to be there and were being brought up to RAF spec.
Very happy days - all eight of them
Edit to add: It occurs to me that certainly during the 70s the air cadet fleet of VGSs were equipped with the Sedbergh and Kirby Kadet T3. The T3 definitely had a green inner cockpit (more than eight very happy days this time
) as these types were often co-located I wonder if the mists of time have just conspired to blend these two details?