Stupid question for colour-blind gamers: why do accessibility options in games remove and mute colours to simulate colour blindness types? (i.e. protanopia, deuteranopia, etc.)

I imagine if you can’t perceive some colours, you want hue shift or boost, not to actually remove colours so it looks like what you already are seeing. Feels a bit like muting all sounds to help one with auditory deficiencies. What am I missing here?

I have used Chromatic Vision Simulator on my iPhone with a camera to check for colour-blind accessibility of board games.

https://apps.apple.com/us/app/chromatic-vision-simulator/id3...

It's free. I'm unaffiliated, just a happy user in the past.

Not for gaming, but this was developed for checking plots: https://github.com/hdembinski/monolens

And works cross platform.

Ubisoft is on the forefront for accessibility.

The shader code in Chroma looks to be a direct copy/paste from this old repo: https://github.com/Chman/ColorBlindr/blob/master/ColorBlindr....

I don't see it being referenced anywhere but maybe I'm mistaken.