RIT Color remover sometimes works. Ive been able to get black to Grey. But it always has a sort of yellow Tint. But then a slight tint of blue might give it the right green tone. Worth a shot I suppose.. But this CRM suit has sort of a shiny finish to it which means it is probably a synthetic material which will neither dye nor decolor.
I once dyed a white shirt dark blue and then I needed it white again. I used a combination of Rit color remover, bleach, lime away and Goof Off. and repeated the cycle about 20 times. It took hours.
two of those chemicals combined to make the most god awful stench, I think it was the RIT and the lime away. I think it literally shaved years off of my life it was the most toxic thing I've ever smelled.