CAA Class 1 unrestricted medical can now be obtained by some CVD (colour vision defective) pilots as there is a new more enlightened test related to flight safety and the actual tasks required of flight crew.
This means that some versions of defective colour vision are deemed safe and others are not. There are different types of CVD and different degrees of type.
All very scientific and result is based on ability to distinguish colours safely especially PAPIS so red / white.
What is not so easy to fix is the general perception that "colour blindness" means not safe to fly passengers, especially as this has been the dogmatic situation for many years.
Any airline or operator failing a candidate with a class 1 unrestricted due colour vision test will now be be open to legal claims from the candidate