Stu, I'm sure the Grant Godfathers will step up to the plate but I'll offer my two cents.
In December 1941, General Order 1272 introduced a standard single colour, British Standard Colour No. 61, Light Stone. BSC No 64 Portland Stone also features. In 1942, a more scientific analysis of camouflage needs in the desert by the Camouflage Directorate of GHQ ME resulted in a new General Order. By this time, formations such as 22nd Armoured Brigade and some of the more experienced regiments such as 3RTR were using their own versions of a disruptive pattern camouflage with Light Stone as the base colour. The new GO, 1650 of Dec 1942 introduced a new base colour, Desert Pink ZI, which had been pioneered by the Long Range Desert Group. The disruptive pattern was applied with one of four colours, Dark Olive Green PFI, Standard Camouflage Colour No. 14 Blue-black, British Standard Colour No. 34 Slate or SCC No. 1A Very Dark Brown. The GO provided some templates for the camouflage pattern, although in practice, units "freestyled" it.
Rattle cans are perfectly usable but the range of colours is limited unless you go for automotive paints, which are only going to be an approximate match. They're also relatively crude to use. If you discount the cost of an airbrush and compressor, the airbrush route will be much cheaper in paint costs. You will be very surprised at how economical an airbrush is. You don't need a big can of paint, you can cover an entire Armortek model with about six tinlets or bottles of model paint. If this seems implausible, bear in mind that you will thin the paint by at least 100%, ie a one to one mix. I would probably thin it even further, so your model paints will go a long way. You will also be able to find colours which are much closer to the original. Do have a look at this thread:
http://www.armortek.co.uk/Forum3b/viewt ... ceb9fa572e
There are many options for model paints, which vary considerably in the accuracy of the hue, compared with the original. The AK so-called Real Colours Range purports to be accurate but are generally regarded as being less so. Two ranges which are well regarded by made by Hannants the model shop (Xtracrylics) and Hataka, a relatively new manufacturer who are getting good reviews.
Finally, the acknowledged experts on British WW2 colours are Mike Starmer and Dick Taylor, both of whom have written books on the subject. If you Google Mike Starmer, you'll get a stack of hits with his recommendations.
Hope this helps, Enjoy your build.
Stephen
. So not at all what a Desert Grant would look like ......