[Clamchop]

Traffic lights.

Everyone everywhere knows red, yellow, and green now, and how to navigate around colorblindness (both red and green lights are tinted to be distinguishable).

[deathanatos]

Traffic lights are a combination of color and position; even if one is completely colorblind, the position of the lit lamp is sufficient to discern the signal.

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.)

[quesera]

> Traffic lights are a combination of color and position

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!

[Clamchop]

Traffic lights still work without position, as they'd have to at night, in fog, in glare, and so on.

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.

[throwawaaarrgh]

Colors do not have universal meaning. This web browser design might work in the US, but there are 194 other countries out there. (also, position does not fix the problem of traffic lights for the colorblind)

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.