The CAA colour blindness tests are much more stringent than the FAA. I went through all the CAA hoops unsuccessfully, but passed the FAA tests.
The CAA use the Holmes Wright lantern test which in my opinion is more difficult that the one you get from your doctor/optician. So there really isn't much point in paying the money to do the CAA test. I wonder how many pass it?
You could consider a US instrument rating and a US registered aircraft.
Interestingly, the Australians did a big study of colour blindness and decided that it wasn't anywhere near as much of a problem as previously though. They relaxed their requirement considerably. I wonder what EASA will do?
I assume you have seen this
http://www.pprune.org/medical-health...hread-3-a.html