You can wash it the same day if you want. It won't go away or ruin it. Yes you can wash it whenever you want to.
The highlights are permanent and change the color of the hair but the highlights will appear to darken as one's hair grows out in its natural color. The effect of blonde highlights usually lasts about 6-8 weeks before the hair needs dying again.
3 inches
No, it will harm your hair in the long run.
2 weeks depending on how strong your hair is
about a month
depends how long ur hair is it also depends on how thick you would like your highlights typically it takes about and hour maybe and hour and half
You sure can get highlights over highlights. The more highlights you get though, the drier and courser your hair will get. I have long brown hair I got golden highlights in June 2009 but I didn't think they were deep colored enough so I got them again in November 2009. She got them a little brighter in November which I like more but then I had gold and blonde and of course brown. Just this July 2010 I got touch up highlights and they were a mix of gold and blonde and I love them. They will keep me satisfied for a while so that way I can get my hair back to a soft silky feeling!
Cap highlights are old fashioned or for home use. In the salon cap highlights are mainly used for men's hair because it causes a lot of pain to people with long hair. Foil is used on long hair. It keeps in the heat and the hair processes (changes) quicker.
2 to 3 months
There shouldn't be a problem to get hair highlights, as long as you go to a professional. However, if you're hair is too damaged from previous colorations or bleaches, maybe it's better to wait until your hair is healthier or have a hair cut.
like in 2 or 7 days
It only falls out because you may have left the hair die in your hair to long Or your hair may not like the product you have used.