ClairolRoot Touch-Up by Nice'n Easy Permanent Hair Dye, 6A Light Ash Brown Hair Color, Pack of 2

Great coverage for white hairs, the best thing about this product is that it stays on the hair so you only do the retouch on the newly grown hair, you don't need to do the whole length like with other products that fade in a couple of weeks. The black matches my hair perfectly so I only do the white hair patches and sometimes only use half of the product for one quick touch up, I love it, it's the only one that stays forever and doesn't transfer on your hands and clothes.