The black band in the middle will fade out with time, but it should still be visible.
I use the black band as a measuring tool for how wet I want to make the bristles. Starting at the tips, and label the sections 1, 2, and 3 on down to the ferrule. I stand the brush knot down in a coffee cup, and add just enough water to cover section 1, up to where the black begins. This is all I need, most of the time. For thirstier creams like Musgo Real, I go up to section 2. Keeping section 3 dry will help keep the brushes backbone nice and stiff.
Of course, for rinsing after the shave, all 3 sections get wet. They have to, in order to get all the lather out of the breach of the knot.
Does anyone have a picture of what this brush looks like broken in?