When the greens first came out - there was a market to die the stock black - a better option than duracoat. However - unless you paid someone, you need to be a little cautious.
Some have had it come out splotchy or purple tinted. Then again - others have had it come out perfect.
I have read that you add green to the black die to keep it from turning purple...
IF it were me - by the time I found a container to die it (and I think ya gotta heat the water), I'd just assume pay someone the $ to do it for me. There used to be a guy advertising on Gunbroker. But as the black PS90s came out - I think there is less demand for this.