I’m a little more out my comfort zone there (i.e. Need to check) but I think the later ones (AEW) were overall Dark Sea Grey and that might have been the colour on white/grey ones (Early ones were of course MSG over white!!)

Well I have to ‘fess up here,
I am wrong and Dave is right about the grey used on Shackletons.
AP.119A-0601-1E (Jun ’72) which was the official painters and finishers guide states,

‘Maritime Reconnaissance-piston engined:
Gloss dark sea grey upper and lower surfaces
BS381C/638
Except top of fuselage which is to be gloss white.
On NEAF aircraft only, this white finish is also to be applied over wing fuel tanks.
Serials and ID letters in post office red with white edging.’

Obviously that covers the MR.2/3 Shacks, but as the codes and serials are presented in the same way it is fairly safe to assume the AEW.2s were finished in the same gloss dark sea grey.

I’m still surprised by this as the grey looks a slightly different tint/hue to me than that used in the camoflage scheme of the fighters/bombers of the era. Maybe its’s the gloss content, HSA’s paint type, or the fact that there is just so much more undisrupted grey on show which has thrown me?

Thanks to TonyT for the AP and DaveF86 for raising the issue with me.