I guess the only way to achieve it is going to be to blanco everything in either 'sand' or 'natural webbing' blanco from SOF.
I just have a set of unblancoed webbing for use in Italy/desert type settings. I'm certainly not going to scrub the blanco off it. The small pack is one of those SOF repros as things as decent original unblancoed small packs are as rare as hens teeth these days. It isn't bad although the material is a bit wierd compared to original stuff.
McV will now no doubt find a crate full of unissued small packs at a car boot sale...