How to remove color from a flight suit

I was able to get a used flight suit for next to nothing. The only issue is that it is a beige color and I need it to be a grey. Any suggestions?

If the suit went through a vinegar wash this may be difficult. I would try some color remover that I believe RIT sells. But you might try just detergent washing it and see if that helps any.

Find a product called RIT color remover, and pick up 2 packs of it. You can pick some up at Michael's craft stores or most any fabric store. Get yourself an enormous tub. Boil up a stock pot full of water (or several), and dump it in. Mix in enough cool water so that
1: there's about 5 or so gallons of water
2: the water temp is around 160-180 degrees Fahrenheit.
Dump in the color remover packs. Do the dumping in as close to the surface of the water as possible, so the chemical dust doesn't get into the air.
Immerse your flight suit and start mixing and churning it around in the water and dye remover bath with a disposable stick, such as a piece of scrap wood. Push the flightsuit left-right and forward-backward inside the tub with the stick. Do this for about 20 to 40 minutes.
Dispose of the color remover bath, and rinse out your flightsuit with cool water. Rinse it several times, until it stops smelling like the color remover.

Repeat this process with the gray color you want to dye the flight suit.

fantastic! thanks for the information