If you dye your hair dark brown looks black and want to go lighter can you dye your hair light brown will it lighten it?

Yes, your hair will lighten slightly, if you only used a dark brown tint and not black, (black is impossible to remove).

Try a Level 5N with a 20 volume cream developer. This will slightly lighten the color that you have now. You could even mix the 5N with a little bit of 6N, just to give it a little boost in lightening.