Dye them. Use a colour remover first, then green dye.
Blue and green.
you can buy any navy blue dye from your local art store. Iv'e done this quite a few times
It can be one of two things: a green dye, or a mixture of blue and yellow dyes.
Blue,green
Green dye is made by combining blue dye and yellow dye, which can both be made from Aggie, the dye maker in Draynor village.
the outcome should be a darker (more blue) shade of green.
brownish black
Blue and Yellow dyes
A rather muddy black.
poopy color
yellow