Help - blue hair!

[Megan-Kathleen]

I have used a purple colour on top of blonde hair (base 10) and it has come out bright blue!
Does anyone know why this has happened and what you would do to fix it?

Colour used was affrinage pure purple from the dynamics range with a little colour mix /76 which is purple.

 

[andreacrosby]

This has recently happened to me , she's been blue before so was cool with it but we wanted purple this time