For your Workrite Coveralls needs

I found this site that sells the Workrite Coveralls from the new film. There really cheap compared to other sites.

https://www.froutlet.com/Workrite-7-oz-Nomex-MHP-Navy-Deluxe-Industrial-Coverall-188MH70NB

Not a bad alternative, the real ones were the 9.5 oz Indura UltraSoft in Charcoal Gray but these could definitely work. Good find

Also if you can only get you hands on navy or grey etc
I found out Rit has a liquid fabric dye bottle called Charcoal grey it looks just the movie coveralls color.

You could take the blue ones and dye them charcoal grey all your weathering right into one

Charcoal grey as people mentioned is the correct color.