I have been in your shoes a couple of times myself - before you dye it again try using dawn dish soap it helps take out some of the color because it is so powerful you can also use orange juice sometimes the acid tones it down also. Try these before atempting to dye it again. You need to lighten it up this time so it is going to be a bit trickier. I have naturally med. brown hair and wanted to up the darkness but I went too. dark- my ends pulled the color in and my roots didn't change at all so i decided to try to lighten the color up with an all over lighter shade and it all turned reddish- brown- very odd combination- so I ended up having to go to the salon and spending an armand a leg on a double process hair color- I recommend you have a professional re color your hair if the dawn dish soap and orange juice don't work- Good Luck.