> if that's true then it's also shocking how little effort seems to be made to compensate for colorblindness.

Note that making something accessible to colorblindness doesn't mean you can't use color, it means you can't use color to differentiate. So a graph with a red line is fine, as long as the color isn't what tells you if the movement is positive or negative (and the graph is the magnitude, if that makes sense).

Red numbers on a excel sheet are probably fine too, as long as there is some other signifier on the cell that says "this is bad" (like parentheses or a negative sign).

Green/Yellow/Red lights on a status dashboard can violate accessibility, unless there's text or a shape that goes along with it.

Also there is varying degrees of colour blindness. I have mild case. Where I have hard time to differentiate certain shades from each other, but clearly red or green is like traffic lights is still easy to distinguish.

So something like a graph might not be an issue if shades are properly selected.

> if that's true then it's also shocking how little effort seems to be made to compensate for colorblindness

Yes, it is!

I also don't like how when 'colourblind mode' does exist, it tends to be wildly different - whereas I don't need that, I just need slightly different reds and slightly different greens that don't mix up. I do realise though that it's probably because different people have different ranges, and the far easier/only possible way to fix it for everyone is to go blue/yellow or whatever instead.

It is less, because that stat is for whites. Colorblindness is hereditary and more rare among blacks. Even among whites, some regions of the world have a lot of it (Hungaria), others less.

The other reason is that most of it is subtle colorblindness. Those people don't see black and white, they can distinguish primary colors perfectly fine. They have trouble with waaaay more subtle differences between colors - when you add a bit of green to rgb.

Yet other observation is that with exception of electricity where color codes are confusing ever for people who complete vision, the colors used in traffic, in graphs in books, in toys for boys actually tend not to use subtle shades.