http should simply be RED https should not be indicated at all
A curated list, preferably by the gov. should indicate which SSL certificates are allowed to be green.
Government oversight of TLS certs? No way this could possibly go wrong
Everyone everywhere knows red, yellow, and green now, and how to navigate around colorblindness (both red and green lights are tinted to be distinguishable).
The above suggestion doesn't have that sort of double-encoding of the data.
(This holds even for the odd horizontal signal, though I would expect most non-colorblind people would not be able to tell you the orientation from memory.
… and … there are plenty of drivers on the road who, judging from their behavior, would appear to be incapable of determining the color of the signal.)
There are some places in the US where the traditional 3-color traffic light is mounted sideways.
I don't remember if it's RYG or GYR. I would expect this to be confusing to a person with the right kind of color-blindness!
Point is, the meaning of the colors appears to be universally understood thanks to driving, and distinguishing the colors has been addressed.
If there are exceptions, I suppose localizations and accessibility modes are just the thing.
The idea that everybody else should have to change to fit crap design isn't a good argument. The design should be fixed, not monkey-patched for everyone but one use case.