Just another advert except what caught my eye was the spelling "colorist". But then I also noticed the spelling of "color". The spelling of colour without the "u" is considered by many to be the American spelling, but whether it is or isn't, it is a secondary spelling in Australia.
It does however make you wonder why a company that can afford such a large advertising budget would use secondary spelling variations rather than the preferred Australian English spelling. On the company's About page they've used the spelling colour, ("we do not promote do-it-yourself home hair colouring") which does indicate inconsistency.
My concern with advertising signage which doesn't use the preferred spelling is it can cause confusion when people regularly see alternate spelling variations. Buses are regularly used by students and I'd be fairly certain most teachers would mark the spelling "color" as incorrect.
Kelvin Eldridge
www.Australian-Dictionary.com.au
The preferred Australian English spelling.