Root coloring kits are so wonderful because they cover the gray (making me feel better) in only 10 minutes! Also, using color only at the crown instead of all over is so much better for the hair!
The latest kit I tried is the L’Oréal Paris Root Rescue 10 Minute Root Coloring Kit ( $7.99 USD). The description of this product is:
Do more than touch up your roots – rescue them. Introducing the next generation in the root touch-up market that merges color with care and convenience. With a breakthrough applicator, guaranteed shade matching and a conditioning formula, covering grays and roots has never been so precise or easy. Just mix and color your way to seamless coverage – all in just 10 minutes. Featuring a unique conditioning low-ammonia formulation that rescues strands with a revolutionary, flow-through, self-contained root applicator brush, eliminate the mess associated with the standard at-home color bowl and brush. The ultra-caring color gel pampers every strand as it covers every root with seamless, shade matching color. Available in 12 shades.
What I think: I have dark brown hair that really shows the grays. My color is Dark Brown #4 and it matched perfectly with my hair color. Plus 10 minutes was just enough time to completely cover the grays while looking natural. The applicator brush worked pretty well, but it was kind of bulky and hard to get in the roots. I had to wriggle it in there. But since the coverage was great, it worked out okay in the end!
You can purchase this kit at drugstores and mass market retailers near you. Enjoy!