Take photos and keep sample swatches of the fabrics too.

I'd find some twill. That is pretty durable and fairly lightweight. Check near the denim & bottom-weights section of the fabric store for it. It comes in neutrals and some brights.
I don't know if they still sell brush-popper anymore, but it is lighter weight than denim and is designed to be made into long-sleeve shirts to protect your arms while riding through or working with bushes that would like to chew up your arms. That would also work.
I am with the others, I'd be more concerned about the wear the top is gonna take!
Good luck!