it seems to me that CAA just cant make up their mind what passes as colour safe and what doesn't. The standards are different from all different parts of the world. Here in NZ for my class 1 i failed the ishihara test, but passed the holmes wright lantern test, but i was still slapped with a colour vision endorsement.. *odd*. Apparently i can work this endorsement off if i pass some other tests, but if i were to pass the holmes wright in other countries i would be sweet!
If ya ask me they really needa sort them selves out and get some international standard, if they really need one at all..
The idea of a test that actually relates to what a pilot might experience is a very good one indeed.