David Aiken recently posted information about hobby paints in response to a question about A6M3 colours over at Hyperscale. David cited Tamiya XF-76, Sweet and Gaia paints as all being versions of the 'Hairyokushoku' (Grey Green Colour) paint used on the Zero.
This kind of unequivocal response is rather misleading if not mischievous. Firstly the three paints are not at all similar to each other, as I have demonstrated several times in the past and as the images above show. The Tamiya paint is not a 'traditional' grey green but is actually closest to the current appearance of the paint on surviving examples from Pearl Harbor era Zeros. It is between Munsell 10 Y 5/2 and 10 Y 6/2 in dry, applied form.
The Gaia paint is based on the grey green 'M' series in Kariki 117 which some researchers have suggested are cockpit interior colours. It is a light to mid-toned green between Munsell 7.5 GY 5/2 and 7.5 GY 6/2. It is nothing like Tamiya XF-76 or Sweet #1, saturated or un-saturated!
The Sweet colour matches Pantone 5783U, cited in the instructions for Sweet's diminutive 1/144th scale Zero models and supposed to represent a 'scaled' version of the Zero colour. It is very similar to the RAF colour Sky. A brushed out sample of this paint is darker than the RAF Museum chip for Sky but lighter than the current BS 381C chip for 210 Sky. It is nothing like the Tamiya or Gaia paints, saturated or un-saturated!
Unfortunately David sees fit to either ignore or to disbelieve this evidence, which has been obtained by actually testing the paints, but instead to rely on printed images of paint charts and/or of paint bottles!
Secondly, there is no formal documentary evidence that the production Zero was actually painted grey green - at least not the grey green that David is suggesting. There are only two, known, official descriptions of Zero colour. The first is from the maintenance manual published by the Kaigun Kokuu Honbu (Naval Air Headquarters) which at section 3.1 under 'airframe structure' states that:-
Toryou wa kouzou naibu ni toumei toryou (tan ao iro) wo mochii gaimen wa keikinzokuyou tokusho toryou (hai nezumi iro) wo hodokoshi hyoumen wa migaki shiage nari.
(The paints to be used are transparent paint (light blue colour) for the interior and special paint for light metals (grey rat colour) for the exterior, and the surface is to have a polished finish.)
2,000 copies of this manual were distributed to the commands of all air related units for use by pilots and ground crew.
The second reference is in the YoKu No.0266 report dated February 1942 which states that the current colour of Zero fighters is J3 Hai iro (ash or grey colour) (but) slightly towards ame iro (amber or caramel colour).
Both descriptions suggest a warm, slightly brownish or olive grey (exactly similar to the extant paint samples) rather than the pale grey green suggested by David's post.
A check through earlier posts here in the 'Zero Colour Conundrum' series will provide more details and examples of the actual colours found on the Zero and j-aircraft.com has many more.