What's the best over the counter hair color you can purchase to deal with stubborn grey hair?

I bought some Tres Semme shampoo for coloured treated hair. But I can already see the grey returning in and around my scalp.





I used L'Oreal Iridescent Mahogany Dark Brown (G25) to cover my hair a week ago. Had a hairdresser friend apply it for me to make sure I got the best coverage throughout my hair.What's the best over the counter hair color you can purchase to deal with stubborn grey hair?
use the loreal haor colour protector shampoo and conditioner...as it is designed to go with the loreal colour chemicals.





but the real trick is to wash only in luke warm water. Hot water leaches the colour out really quickly.What's the best over the counter hair color you can purchase to deal with stubborn grey hair?
I go to beauty supply stores. Do you have Sally's in Canada? If so, I like Wella. I don't have grey, but most dyes just wash out of my hair.
Well now, I have no idea how to get rid of gray, but would like to keep the dark roots at bay. I use L'Oreal blond something. lol
I use henna....my natural hair is red....so it works OK. I think going to a professional beauty supply store might be the best bet if you're not willing to experiment with plant based tints.

sell makeup