Your best bet will be to either go ahead and purchase the wig, or purchase some spray-in hair color. Any black temporary hair dye will most definitely leave your hair black (or at least reasonably darker) for a lot longer than after one wash. Another...
Okay what ever color you put on your hair b4 already messed up the color of your hair because it prelightens b4 it deposits color so stripping will leave you with orangey hair you can bleach and be fine just make sure you process all the way to a pal...
more then likely it will take up the color but just to make sure go to a beauty supply store and buy yourself some color correction product and put it on your hair so that it gets rid of all the colors that you have on your hair and it gives it a mor...