I have blue, purple and pink in my hair but it washes out really quickly so I'm constantly re-dying it. It fade after I've washed my hair about 3 times. Could it be washing out because of the shampoo I use? I also straighten my hair every day, could that also cause it to fade out more quick? What could I do to make the color last longer?

If its not perminant its not going to stay in there very long
If you want to keep these colours I suggest you go to your hairdressers and get it done permantly then it will last a lot longer.
:)

I talked to my cousin who's a hairdresser and she said you can't get those colours permanently done.

Do you know of any brands that make those permanent colours?

Hmmm that's a tough one he he as I'm no hairdresser
And I don't buy home based dyes as my dads girl friend is a hairdresser so I get done almost free.
Sorry I couldn't be more help

Heh thanks for your help anyway

Hair dyes such a blue, pink and purple are unnatural neon colors that are temporary or semi-permanent. These types of colors will wash out. If you want to color last longer, try using shampoos & conditioners made just for colored or dyed hair.