The best and safest solution to covering up roots is using a root spray or powder until you can see an expert, says Lee. Root sprays and powders are temporary dyes that cover greys and wash out when you shampoo. Try Color Wow's Root Cover Up.
For the root area, use 20 Vol unless the hair is really really dark. Once the hair has been lightened correctly, you should only need to use 20 Vol developer with your color.
Hot roots occur because the heat from your scalp causes the colour at the roots to develop faster than the colour on the mid-lengths or ends. This can lead to a lighter colour result at your roots than the rest of the hair.
First, part your hair as you normally would. Then, dip your painting brush into the dye and paint the colour onto the roots. "If you're covering greys, it's important not to overlap onto your coloured hair. If you're doing a root shadow, you need to paint past where your regrowth line is," Jaye says.
“The No. 1 rule when touching up your own color is put color only where it's needed — on the roots,” said Jaxcee, a colorist and a founder of the Coily Collective at the Riccardo Maggiore Salon on Fifth Avenue. People mistakenly think they have to pull the dye through the entire length of hair so it will blend well.
Root Touchups
They can be very safe and effective when a professional uses them. They also do not create any higher a risk for complications for hair loss or hair growth than traditional hair coloring. There are other root touchup products that you can buy at stores.
Colors like butterscotch, light auburn and golden brown, or ash brown for those with a cool skin tone, are all versatile brunette shades that aren't too dark and are some of the best hair colors to hide gray.
Neutral shades like soft blonde, mushroom brown, light copper, and caramel blonde balayage are the easiest to blend gray into (and maintain over time without wanting to shave your hair off).
Expert colourists recommend a darker shade of dye for your roots and a lighter shade, that matches more or less your natural hair colour, for the rest of your hair. Start by applying the darker dye to the roots up until an inch or so down. Then, use the lighter shade for the rest of your hair.
Take a section. If you're dyeing your whole head, and it doesn't already contain any colourant, dye the mid-length and ends of your hair first – hair at the roots will take colour much quicker, so leaving that until last will give your final style a more even colour.
It's always a good idea to give your roots the most time to absorb color—say about a 20-minute head start from the rest of your hair. After that, you can gently comb the hair color down your hair, adding more color to your mid-lengths and then finally to the ends.
These highlights go all the way to the root, and the dyes used to do touch ups are actually affected by the body heat coming from your scalp. That means, if you have more than an inch of hair to touch up, the colour may look inconsistent. For this reason, you should plan to have your roots touched up every 4-6 weeks.
Root care 101
Ideally, you should be visiting your stylist for a root touch up every 4 to 6 weeks, and no later than 8 weeks. This isn't purely because it'll look better, but for biological reasons, too. Your scalp gives off heat, and this heat won't extend much further than 2 centimetres past the root.
Choose a tinted gloss to correct your highlights, or a clear gloss to add shine. Use a root concealer for a temporary fix. Grey root concealers come in spray, stick, or powder form. Apply a root concealer to your roots and let it dry or set if needed.
How often should I touch up grays? If you're dealing with a lot of gray hair, you should touch up every four to six weeks. If that sounds expensive—and time-consuming—that's where at-home coloring is key. With it, you can keep the hair color you know and love—without spending a ton.