Why didnt the die last permanentley??

Question

i bought blue black hair dye from shoppers drug mart its garnier fructis it lasted for about 2 days and then it just disappared??

why is this

Answer 1

When you die it is permanent. When you dye, it might not be permanent.

Answer 2

First, why is this in "word play"?  Because the dye was supposed to be "permanent"?

You likely didn't leave it in long enough or your hair could've been oily or something like that.  Any number of things could affect it.