I hadn't had a chance to make an appointment to get my hair colored yet and I ended up with last minute plans to go out, but did NOT want to be seen with my salt and pepper roots! So on a whim, I grabbed my eye brow pencil that I never use anyway and rubbed it over my roots and it covered the gray! I also sprayed on some hairspray just to make sure it stayed on. It even lasted until the next day when I washed it out.
Mascara is even better and easier.