A copied info piece from Irish Paul - Hope you don't mind bud?

The colour always looks a bit darker at first....it will ` lift` after a few shampooing`s and sun-exposure...... I always give my new systems 2 light shampooing`s...you`d be surprised how much ` excess` colour comes out....last system, the water went a really dark shade !
If you took your hair sample from the back/crown area, that hair is always darker than at the front/sides so it`s worth bearing that in mind....take bits of hair from a few areas.

Your post is a constant new piece question- above are the first things you should do to try and tone the color down. Regards