I was going to dye my hair black (my natural hair color is dark brown) with the kind of dye that washes out in 28 shampoo's, will I get my natural hair color back afterwards? Help please!

There is always a risk of residual hair color staying in the hair, even after 28 shampoos. It depends on the health of your hair and the properties of the hair color. If you are afraid of it at all, don't use it. If you still wish to go ahead with the dark color, if it still isn't faded out as much as you would like after 30 or so shampoos, try shampooing with dish soap (such as Palmolive) up to twice a day for up to a week. Then be sure to deep condition your hair to counter the drying effects of the dish soap.