Count me in on this project... Nice work, Zissou, on getting this thing organized!
I second everyone's suggestions of red, green and possibly salt and pepper options. In my opinion though, super-black, and all white do not work very well as a chambray because it's the subtle imperfections in the fabric, slubbiness, and contrast between warp/weft which give the fabric its charm. All of that would be nearly imperceptible with black or white.
Frankly though, I hope blue is an option as well (either blue-green or a slightly darker indigo). Yes, every brand out there makes a blue chambray... but for those of us who are 6'2" or taller, and/or with a muscular build, it's near impossible to find one which fits well. Most of the Japanese brands only make up to size 42 or 44 chest. Even if I can find a 46, it's usually too tight in the shoulders, and/or the arms are too short. Thus, MTM is the only option for a blue chambray that fits as I'd like it.
Apart from colour... I like the idea for chin-strap, selvedge gussets/accents, asymmetrical pockets (more workwear than navy-style), and triple-stitching around high-stress seams (shoulders, yoke, etc.). Thread colour seems like an option which would be very easy to leave up to the buyer... although it sounds like most of the other details would probably have to be standard.
All in all, I'm looking forward to seeing how this project develops...