I never thought I would use a product like Style Edit Root Concealer, which costs $25 at salons; it is currently $17.50 on Amazon (Nov 2017). I had been having problems with my grays coming in much more rapidly than in the past during the last few months, as well as trying different home hair coloring kits with a few failing to cover the roots very well. After re-coloring too soon after a fail and discovering my hair had become like straw, I became desperate for something to cover my gray roots when I have important trips/events and it is too early to re-color. I woke up to an Instagram story by Whitney A who is a 35 y.o. who claims she covers her gray roots with this. The Style Edit website lists salons in your area that sell this product. I found one and tried it right away, and I have had good results.
FYI, there is a dupe -- the Everpro Gray Away is around $10 or $11 at drugstores and you get 1.5 oz (around $7.33/oz), compared to 2.0 oz of Style Edit ($12.50/oz at salons, $8.75/oz on Amazon). Basically they have VERY similar formulas and work exactly the same. I think they are both okay but neither are great value, because you do not get very much. But when you have a serious time-crunch emergency, like an important event and your roots are showing but you do not have time to touch them up, this will save your life.
The instructions tell you to shake the can frequently and spray with the pinpoint spray nozzle. And here are some additional tips. Make sure you know where the nozzle is pointed and spray in short bursts from an angle to where your hair needs coverage, so more gray gets covered and the spray isn't concentrated in one spot. It really does blend into your hair and is not perceptible.
You are supposed to apply AFTER you have finished styling your hair. I do it after I have used hairspray to set. And then you are not supposed to touch it for 3-4 minutes. I've had no problems with transfer. I have slept with it in my hair and it does not transfer to my white pillowcase. I have not had it drip, run or smudge with minor workouts. I have not been caught in the rain with it. If you scratch your scalp near where your roots have been sprayed, it will probably get on your fingernail, but I have not had transfer with running my fingers or a comb through it. It stays in your hair until you shampoo it out.
I found this product gets used up FAST! I really think it works well, but I will probably buy the Everpro Gray Away over this only because the Everpro is virtually the same thing and it is far more easy to get everywhere. Style Edit is available only at salons at the $25 price or on Amazon for about $8 less. The Everpro is not really a better deal, but sometimes there are coupons, especially if you buy at Bed Bath & Beyond.
My hair is between Light and Medium Ash Brown, and I can use anything between Medium Brown and Light Brown. I plan to also try the L'Oreal version and will update with a comparison.