I have heard about a week to a month. I have never tried it, but the most I can tell you is to keep researching. I'd invest in Manic Panic if I were you. Their colors lasted in my hair.
Yes but not sure because with color dye it is going to take a few washes. See in my hair I have pink washable spray can tips on the bottom of my hair and when I was it will come out right away, but with color dye it may take a little while.
I did this. After I dyed my hair black, it looked really good. But every time I take a shower, some of the color comes out, and my hair has small random red tints, but it looks okay.
it depends on how much hair is in the brush
it depends on whether or not it is permanent, and whether or not you are a blond. If it doesn't come out in 1 month, you will have to shave your head.
depends how long your hair is now
Pretty long
it matters how you wear your hair
Hour
Less time than the hair on your head. hair is hair.
TO DAM LONG!
you have to have certain genes, my hair grows an inch and a half in a month. but it will take about half of a year to grow it really long
Could you check to see how long it takes to system and hair