Haircolor mishap please help?

I decided to color my hair at home so I used a good brand Excellence Cream. It was supposed to be "light brown" natural tone. WELL i followed the directions to a tee and my hair is dark brown with reddish tones to it! I hate it what can I do to make it fade and take out those reddish tones. I would have thought NATURAL was not warm/reddish tones but whatever...help!!!!!