Whilst the F-4 had various shades of Barley Grey, that pre-dated the FunBus grey by 16 years....
Never heard anyone call it Barley Grey - and we hated the original grey withthe pansy 'blue vein' and white lettering scheme as applied to ZA149! I picked it up in July 1994 from Boscombe after 'les Girls' had brought it back from its heat soaking trials - a thinly disguised holiday in Lost Wages for them, we thought.
It was then found to be still full of boffin wiring which hadn't been added to the weight and balance schedule, so didn't fly again for a while until Boscombe sorted out their paperwork.
And yes, I did christen it 'John Major grey' at the time!