What I find quite ironic is that the UK's effort to combat this problem, by adding a blue tint to their green lights, actually makes it more dangerous for peopl

What I find quite ironic is that the UK's effort to combat this problem, by adding a blue tint to their green lights, actually makes it more dangerous for people with my form of colour blindness (protan, which is not the commonest form of red-green blindness but is still significantly represented (2% of males according to Wikipedia)). That's because having little red vision, at night I mistake cyan ("green") go lights for white street lights. Having street lights suddenly turn to yellow stop lights is unnerving, to say the least.