Is it true that true blondes have dark roots but fake blondes have light roots ?

Not positive about the fake blondes thing, but I'm a true blonde and I've always had dark roots. I actually started dying my hair cuz I was tired of people making assumptions that I wasn't a true blonde.Is it true that true blondes have dark roots but fake blondes have light roots ?
It could very well be, I for one, had darker roots come in as I got older, fake blondes have fake roots, so it stands to reason they would be lighter...