Should I wash hair before having it coloured?

[Ifonlyiweretaller]

I'm having it done tomorrow, and never know whether i should wash it with a mild shampoo (bavy shampoo maybe?) before I go to the hairdressers. If they put the colours on and it's not totally clean (which it wont be due to hairspray/mousse etc) surely this will affect how the colours absorb? I know it gets a good wash afterwards, but I just wonder if it might help to do it beforehand as well? (cant believe i'm asking this now when I've been having colours done for approx 30 years!!)

My hairdresser says no as the oil in your hair protects your scalp better

Thanks Jeaux90 (great name by the way). So nice greasy hair until tomorrow afternoon then

I only ever do home dyes but every one of them says to apply to dry unwashed hair so no I wouldn't.

I wash my hair once or sometimes twice a day, I colour often. Don't think it matters?!

Thanks Ifonly

No it's much better to leave it dirty than have it freshly washed

Thanks all. Can't wait for my greasy, product filled hair to be transformed later on!