WW2 British/Commonwealth armor colors (that would be "armour colours"

). This looks like a good match, but as you suggested, in Tunisia this would most likely would have a sand color weathering pattern. I'd personally go for the sand color wash to get "dust and sand" into the nooks and crannies. The paint could use a bit of fading, but not too much - the Crusader Mk III in Tunisia wouldn't have been in service as long as the older desert tanks. Still, some weathering for age and character would be great. Add a lot of dust - look at photos to get an idea of how much dust collected on the upper surfaces of these things. This is a really pretty model. I have one kit, but I may get a second one for this color scheme. The first one will be desert pink and charcoal black-gray. More pictures as you go, please.....