As far as I know Cathay doesnt actually have a policy on colour blindness - ie. they won't reject you outright- so you might be able to get an interview and come here and do a medical.
The Hong Kong CAD will essentially accept you if CX does.
What you should do is contact Dr Robert Cox at Cathay City. A phone call or email to him will clear up lots of things for you. He is very knowledgable about these things and also the man with the final say - if he can ok your condition then recruitment probably will accept your application.
Suggest you call CX in Hong Kong and ask for his office - if he is not available at least they should give you his email adress and you can contact him.
