If you dye it dark blue ist should come out green of a sort.
Dylon now do a dye based washing pack both blue and black. Use the entire contents like washing powder.
1 wash jacket, spin dry and put to one side
2 dump dye mix in washing machine ( open the packet in the machine, this prevents dye dust spreading around kitchen)
3 lay a old tea towel over dye powder (this prevents contact staining of jacket)
4 place in still damp jacket
5 hot wash
6 hot wash again with regular powder.
Now do a bleach wash to make sure all of the dye traces are gone from the machine!
I have dyed all sorts this way including lurid cammo. whit turning it into something more sedate and less military.
Sandsnakes