Hanna hair coloring would be the easiest to do at home.
Matrix socolor mixed with Matrix Solite 20 cream developer,, leave it on the roots for 20 minutes and mix the rest of the bottle with water and comb it out the the ends the last 10 minutes, and shampoo out..
I do my wifes hair, nice to get in the shower after 30 minutes and shampoo it out...
Lot of fun....and kind of interesting spicing it up. lol