MIDDLE EAST
Middle East practice was determined by local General Orders and, due to supply problems, more variation is apparent than that in Europe.
1939 - 1940 GO 370
specified a basic colour of BS. 62 Middle Stone with a disruptive patterning of 'Dark Sand' in style similar to M.T.P. 20. This scheme appears relatively common in Egypt in summer of 1940.
1940 - 1941
By mid to late 1940 many newly arrived vehicles and tanks appear to be painted a plain overall colour. The normal colours seem to have been Light Stone No.61 or Portland Stone No.64. BS.52 Pale Cream is cited for the 6 RTR new A9 cruisers.
Pale Cream No. 52
Mix: 74 (Linen) 
+ 34 (white) + 103 (Cream) 
in ratio 4:3:2.
Description: 'Pale cream' describes this nicely - a light rich cream colour.
November 1940 GO 297
This scheme comprised the tri- coloured disruptive designs now known as 'Caunter Scheme'. Very many AFVs and softskins carried this scheme of
- Portland Stone No. 64 base with
- Silver Grey No. 28 and
- Slate No.34 or Khaki Green No. 3 in angular disruptive stripes.
Period G.Os specify Light Stone No.61 or Portland Stone No.64 at various times and a local variation substituted a mixed light blue-grey for Silver Grey No. 28.
February 1941 - G.O 63
Single basic colour of Light Stone 61 with up to two disruptive colours applied over. These colours are specified as Slate 34 and Silver Grey 28 still in the angular disruptive stripes as before
and cancelled GO 370 of 1939. This remained the predominant scheme during 1941.
Silver Grey No. 28
Mix: Humbrol 74 (Linen) + 145 (Medium Grey) 
in ratio 5:2,
or 74 (Linen) + 34 (white) + touch 27 (Sea Grey) approx. WEM AR B 08 is very good match.
Description: Neither silver nor grey but a medium yellow-green, fades to blue-grey in extreme.
Slate No.34 a.k.a. dark slate.
Mix: 32 (Dark Grey) 
+ 81 (Pale Yellow) 
+ 117 (US Light Green) 
in ratio 4:2:1
or 111 (??) + touch 102 (Army Green) as fair alternative. Fades to grey about 111.
Description: A darkish dull grey-green.
Middle Bronze Green No. 23 a.k.a. Khaki Green No. 3/ G3/ "Service Colour"
Mix: Humbrol 226 (Interior Green) 
+ Revell 65 in ratio 3:2 approx. If unavailable then Humbrol 80 (Grass Green) 
produces a slightly rich tone.
WEM AR B0 7 is very good match.
Humbrol 30 (Dark Green) 
is a long way too blue and light.
For dyed canvas tilts use Humbrol 117 (US Light Green) as a basis.
Description: In its gloss form this is a dark rich yellow- green contrasting highly with G5 and much less so with G4.
Light Stone No.61 a.k.a. "desert yellow"
Mix: 74 (Linen) + 26 (Kahki) 
in ratio 8:1
OR Revell 16 + 1 ratio 2:1 approx. colour.
In use: 1939 - 43 as basic shade in Middle East.
Description: Medium toned yellow sand colour.
Portland Stone No.64
Mix: 34 (white) + 74 (Linen) + touch 33 (Black) or 67 (Tank Grey) in ratio 4:3:t
A simple but effective mix is 196 (Light Grey) 
+ 74 (linen) + 34 (white) in ratio 7:2:2.
In use: 1940 - 41 as basic shade in M.E.
Description: A pale sand grey/ very pale cream with a greenish tinge.
October 1941 - A Signal 4/105 calls for one basic colour only, Light Stone No.61 to be used before issue to units.
December 1941 - GO 1272 now calls for a basic colour of Light Stone No.61 or Portland Stone No.64, according to supplies with one disruptive colour over at the discretion of Commands i.e. Palestine, Malta, Trans- Jordan etc. This cancels GO 297 of 1940 and GO 795 of 1941. At first this may have been Slate in patterns similar to Caunter but later possibly green, Silver Grey No. 28 and Black have been noted in apparently random patterns.
1942. Over Light Stone 61 the single colour disruptive was still in force although many units did not employ it whilst others used a variety of schemes, designs and colours, some with black and/or white outlining.
October 1942. G.O.1650 cancels all previous patterns and colours and introduces standardised drawings for certain type and classes of AFV and vehicles as decreed by the Camouflage Directorate of GHQ ME (G(cam)). Colours to be used are :- Basic shade - Desert Pink Z.I. with a disruptive pattern in Dark (Olive) Green PFI. Black ( S.C.C. 14), Very Dark Brown ( S.C.C. 1A) or Dark Slate BS. 34 are alternatives. These designs are common on Shermans, Grants, Valentines, Crusaders, Stuarts and the Churchills of Kingforce (which were most probably Light Stone No.61 over Khaki Green No. 3 or S.C.C. 2 in the Crusader design). As Desert Pink was a new colour, Light Stone No.61 continued in use on vehicles with or without disruptive paintwork. Desert pink occurs on its own as a single shade on vehicles of no tactical value and ACVs disguised as 10 ton trucks.
Desert Pink Z.I.
Mix: 34 (White)+ 118 (US Tan) 
in ratio 4:1. A provisional mix. Use as is for model.
In use: 1942-43 Egypt, Western Desert and Tunisia; Introduced by
G.O1650 of October 1942 as new basic colour with disruptive colours on
certain classes of vehicle or on its own.
Description: Earthy pink or warm sandy pink locally produced.
S.C.C. 2 (brown, khaki brown or service drab)
Mix: Revell 84 + Revell 86 in ratio 16:5. Acceptable results can be had with
Humbrol 98 + 29 in ratio 5:4.
WEM ARB05 is slightly light but can be used on a model as is.
Dyed tilts in S.C.C. 2 can be represented by Humbrol 29 mixed with slight
touches of white, black or grey to detail variations in dye.
In use: 1941 – 1945 as basic colour with S.C.C. 1A or S.C.C. 14.
Description: Rich dark brown with a hint of ‘khaki’.
Where dyed tilts were supplied from the UK and Commonwealth they were chemically bleached to a pale brown colour. Although M.T.P.46 had provision for ME colours actual use of this type of scheme has not been confirmed.
Bleached canvas Middle East.
Mix: 29 (Dark Earth) 
+ 34 (white) in ratio 1:1 to 3 depending on requirement.
In use: In Middle East, where vehicles were shipped with Khaki Green dyed
canvas, tilts were chemically bleached.
April 1943 - G.O 1650 is cancelled by a new G.O with standardised drawings for certain type and classes of AFV and vehicles are decreed by the Camouflage Directorate including new colours for Tunisia, Sicily and Italy. Basic shade is 'Light Mud' with Black in standardised bold disruptive patterns for camouflage. Green seems to have been used too. All 'desert' colours to be overpainted. Lend Lease vehicles used 'Light Mud' over US Olive Drab as an alternative. By late 1943 European colours are common. In May 1944 S.C.C. 15 Olive drab is introduced to replace all earlier schemes.
References
The above is from Mike Starmer & Mike Cooper's documents on Britihs AFV camoflauge available at MAFVA
The Humbrol paint colours are from the chart at On Tracks
White Ensign Models do a range of pre-mixed military paints (the WEM references above) . These are apparently the same range as the Xtra Color range available through Hannants and others. The drying time of these paints seems to be very long (6hrs+).
KitReivew.com has an article about Caunter scheme and the XtraColour paints to go with it, including photos of the paints and of Colour Chips from Starmer's book.
ClubHyper review of paint colours for a Stuart, with colour swatches
Matador models descriptions on paint patterns
There is some discrepancy about the colours, see these photos of an A10 at Bovington