Hair color turned out too dark - advice?

Hi,

I just put a permanent (Garnier Lumia) medium brown in my hair and although the color is pretty and the shine is nice, it is really very dark. I have been washing it for the past two days with a mixture of clarifying shampoo and dish soap (followed by intense conditioning each time) but it is still too dark. Permanent colors say they don`t fade, but I seem to remember that they do. Should I just wait it out? Is there anything else I can do (short of stripping my hair, no thank you) to expedite the process? There is really very little about this on the web. Thanks!