Why Grey?

An idle thought passed through my mind the other day. Why was grey selected for noses/engine panels etc on British aircraft? Surely green, brown, whatever, would do as well?
Was it a result of RNAS influence, with grey being a navy fixation with warships, and it passed accidentally to RFC machines?
Was grey the colour of all primers and undercoats, as it is easy to overpaint it?
Were aircraft therefore delivered with this undercoat ready for units to *add a top coat to service specifications, and it was left as it was?
I notice that grey was peculiar to the Brits.

[FlyXwire]

This is an interesting question Neville, and I have also wondered why certain coatings/colors were choosen for use on WWI airframes and coverings.

As far as grey for British paneling, the first question we may ask is whether the Quarter Master General, R.F.C. ever envisioned P.C.10 or P.C.12 to be anything but "stains" to be appled for protective purposes onto (into) organic surfaces? *Your thinking that perhaps naval experience, or direct R.N.A.S. influence may have led to the choice of grey (as a neutral camouflage color) over aluminum paneling is certainly a good suggestion, because more often than not steel fittings on British aircraft were painted black instead, perhaps because more durable coatings were required on ferrous-based metals for their rust inhibiting properties.

Finally, it must be mentioned that the Germans also used a pure grey paint for application over aluminum panelings as well as on steel parts too (like struts), as seen on Albatros Werke aircraft, LVG, etc.. not to mention similar colors of lt. blue to eggshell, to turquoise used on metal by other manufacturers.

Interesting question though, and one I'm sure others here might want to comment on too!? * *

[Yeoman]

Hello Chaps,
Perhaps gray is simply just a good neutral colour that goes well with everything, and is easy to mix

[mossie]

Source: Aircraft Camouflage and markings 1907-1954 by Bruce Robertson:-

Page 11:
"For metal parts, such as engine cowls, the contrator was allowed a free hand. Sober colours such as black or grey were most common."

Page 13:
"Early scouts - natural metal finish, covered with a lanoline finish."

Page 36:
"Naval aircraft - Khaki-green was generally adopted for all aircraft late in 1916."

It would seem that later periods, aircraft were painted in day or night camouflage. This was most evident after the early tractor rotary engine period. Variations existed, and are noted in many places, not just this book.

[FlyXwire]

Easy to mix is always a good thing, but what the heck is Khaki anyway..................kidding, just kidding mossie!

Thanks, chaps. I'm inclined to go with Mossie; Contractor's choice. Seems reasonable.
Easy to mix, probably cheaper pigments...
So, it was just luck; not a specification.

I will leave the rivet-counters to argue over gloss, semi gloss: brush or spray....