Due to budget constraints I've been dyeing my hair at home for the last few months but I'm struggling to get it right. I can now do it without dyeing the rest of the bathroom too but it never come ou the shade I want. I have dark brown hair anyway which I'd like a bit lighter or more interesting (even a hairdresser said it was dull) but it always comes out even darker. Apart from the grey hairs on top which are stubbornly resistant to all dye so far. Where am I going wrong? I last did it 4 weeks ago. It's really dark again (it was meant to be honey brown or something) & the greys are more visible than ever. I hate it. Can I put another dye over the top now or will it turn two different shades?