Prevent low-contrast background combinations

[slifty]

Is your feature request related to a problem? Please describe.

I really value authorship colors, but sometimes a color is dark enough that it makes it hard to read the text. I can't change another user's colors, so I'm left in a tough spot. I checked against WCAG standards and indeed they can fail.

Describe the solution you'd like

Ideally we could (1) constrain the valid colors so that they are only WCAG-allowed combinations.

A second solution which would be helpful for other use cases would be to (2) allow a user to create a "local" color override for a given user, so I can define their color regardless of what they have picked.

Describe alternatives you've considered

Within the current feature set I believe I could either disable authorship colors for myself, or clear the authorship color for the text I want to read, which of course impacts everybody.

Additional context

For example:

Plugin?

I don't think this would make sense as a plugin.

[JohnMcLear]

I'm +1 this.

Side quest: How would this work w/ ep_font_colors?