Is this possible? Is there software to have a magenta or turquoise color filter, for example?

( It's an accessibility issue, relevant to irlen syndrome: I see extra shapes around letters and certain colour filters can help reduce them. You can get prescribed specialist tinted glasses, but when I get those they will be prescription and I don't need my prescription for things that are close up, like my computer screen.

Of course the redlight colour filter in "Displays" that's installed by default is useful, but it's not the optimal colour for me I find. Using Ubuntu 20.04

There is an android app called "tintvision" That does this for phones)