Enter the best root touch-ups for at-home use, which keep roots in line for a little longer at a time. To wit: Justine Marjan, stylist for Gwen Stefani, calls root touch-ups a “game changer” for keeping color fresh at home. And if you need to stave off greys for longer than, say, a last-minute holiday party, there are root touch-up kits for permanent color will get the job (and the coif) done.