I dyed my hair dark brown'' and it turned out black. I figured it would fade but it turned this reddish color in the roots. i did this 3 weeks ago.. How do i get this out of my hair at home?

I've had the same problem, I bought an at home bleaching kit. There are many different kinds, it WILL bleach out ALL color. Then you can put a color of dye that you want/like. It's gonna take some time. Good Luck