Can you use permanent hair color after havign used semi permanent?

Of course you can. Semi permanent dye simply adds color to your hair. A permanent will actually cause your natural color to change. But remember this... color doesn't lift color. Therefore if your semi permanent hair color is darker than the permanent color you are going for---- it isn't going to work. You need to use a color remover before hand. And color removers are REALLY damaging to hair.