At home hair color?

I know everyone will say do not color hair at home... but with Christmas coming and being short on cash, I cannot afford to go to a salon. Which is the best at home hair color? I have highlights in now but want to go one color. Not going lighter. I have a dark brown hair now, and like a light brown highlights. Any suggestions? I was told there's a site that you send them your info on your hair and theyll make a specific hair dye for your hair but I forgot the website name.