I note that ppf says career in aviation, not necessarily helicopters.
I know nothing about the specifics of being a helicopter crewman (other than was quite grateful to be pulled out of the Solent by one on a training exercise once). However, would point out that there are a few corners of aviation where you can earn your living flying with colourblindness.
The ones I know of are as a gliding instructor, microlight instructor, or a commercial balloon pilot.
Of course these may not appeal to you - I don't know, but they are flying jobs, they pay (well, sort of), and colourblindness is not an issue at-all except in the incredibly unlikely event of finding yourself a gliding or microlight instructor at a field which routinely uses light signals to aircraft - and I'm not sure such a place actually exists any more.
G