there are places where you can get professional hair color dyes and get the same results as you can buy the color and the developer in whatever volume you want not only 20 as mostly al boxes have yu can get 30 or 40 volumes.....you just need to know what to buy......

I´ve went to pro hair colorist twice and I look and pay much attention on what they use, brand, quantity, mixtures, etc......

I don´t have grey hair, but most hair color works for me, just have to pick right shade.......