Make setting theme colors much easier

I'd hope for a simplification of theming instead. While I understand some people like the idea of having a such a deep level of isolated customization that you can basically create a different color rainbow in every widget and each editor, I feel like the end result is that mostly nobody ever even dares customizing Blender because it's such an overwhelming task to even do something as simple as changing one single color that's everywhere. Even using addons like pragma37's Theme Editor to make it easier.

And though I am not a dev, I suspect the current theming system isn't an easy thing to work with under the hood either? Certainly doesn't help to cater for visual impairing and user friendlyness.

I like how the Musescore team made color theming simple in version 4:
How We Made MuseScore 4 - Music App Design is Challenging!

We began by establishing twelve colour definitions, each one filling a particular purpose.
The colour of backgrounds, the colour used for text, the colour for buttons, et cetera.
Our rule was that everything in the app had to use one of these definitions.

Now, the trick to the definitions is that they can change their colour depending on the context. If the app is using the light theme, the button colour is this: [] If it's using the dark theme, this: []

This means that when we design something, all we have to do is create it using the light theme, and the dark theme comes for free.
We also created one special colour definition called 'ACCENT_COLOUR', which allowed us to provide theming options for people to choose from.
And the other reason we built this system was accessibility.
In particular, a customizable high-contrast mode for users with various different kinds of visual impairment like low-vision, poor-contrast perception or colorblindness.

I'd love to see Blender take a similar path for the whole theming system. The average user doesn't want more than that.