Getting ready to color my hair again and read the box. Using Wella Color Charm and it says to mix with "appropriate" developer 2:1 (2 parts developer, 1 part Color Charm).

Ok what gives? I used this color before 1:1 with 20 developer and it seemed fine. Should this be diluted to the 2 parts developer as the box says and why? And just what is "appropriate" ? I am obviously not a pro!

Can someone help?

Thanks for your help!!

: )