/diy/ - Do It Yourself

I want to dye these Bundeswehr Splitterschutzweste to light urban grey or dark blue for a more civilian look. I've no clue about dyeing atall. Reading up about it and watching some yt vids but am bit overwhelmed with dye options and lots of unsuccesful stories. I think the cloth is impregnated with some rain liner or something. Thx