Can you mix colors with at home hair color? What would make red?

You can't mix those colors and make red. You could make darker brown if the black and brown are the same brand, but your hair will still be two-toned unless first you make the red part blonde and then use brown on all of it. Blonde dye is very harsh because it lightens your hair by completely stripping the base color, and then depositing the blonde pigments -- so whatever you do don't over-time it. What if you use just the brown dye alone -- then you will have a lighter brown top and reddish-brown bottom?

(I am skipping the obvious and best answer which would be to see a professional stylist. If you must do it yourself I understand but the more you process, the more you risk seriously damaging your hair. Proceed carefully :-))

Can you mix colors with at home hair color? What would make red?

The girl above me has got ir right love!!! Be careful. I know a lady who really over didi her hair and had a bald spot on her head. So be carefull is right. Maybe wait a day or two before trying to fix it!!! xo