Having read through the many pages on this thread, it seems to be that a "practical" test would be more relevant ? Where such tests are undertaken it seems to involve lights being shone from control towers. I am not convinced such tests have any real world relevance at all these days.
Of more concern is the fact that all modern flight decks utilize CRT or LCD displays for primary flight instrumentation and navigation displays. The subtelty of colour interpretation is particularly important with these displays. In situations where a failure occurs to a colour gun or transmitter in such displays, the resulting hues can give problems to people with "normal" colour perception.
It may well be that new tests or existing lantern tests do allow for better colour vision test discrimination, however the importance of good colour perception should not be lightly dismissed from a safety point of view no matter what other countries may do, or however it may dissappoint.