I have un-banded my shirt, rinsed and washed in the washing machine, and here's what it looks like. It's brown with black splodges! Now all I have to do is to tell my son what I have done with his shirt! Ooops! The last pictures in this step are of a couple of shirts I bleached last year. They were both black to start with, but the bleach has made them very different colours. They were tied in what they call "the flower fold". The first picture is of the fronts and second the backs.
If you use a dark blue shirt, you will get pink with blue splodges! With black it depends on the dye of the original garment as to whether you will get brown or grey. Bottom line, it's not boring and it's quick!
Quick Note: for more bleach dyed effects go to http://www.instructables.com/id/Sons-of-Boring-Black/