As far as I was aware, if you have colour blindness of a degree that can be measured and noted, then your medical has a limitation on it. This limitation restricts your ATPL to Australian FIR's only. (Note, I saw this on a licence in 2000). In theory, you could work for QF domestic but you couldn't fly overseas.
I would gather as much info as possible and if need be, see Dr Arthur Pape's website.