META: Provide better support for color and contrast media queries

inverted-colors is widely unsupported. I'd suggest removing it from your list.

Crossing out inverted-colors because of lack of support https://caniuse.com/?search=inverted-colors

Good call @andy-blum.

As far as things we could possibly support.
- Support for AAA colors
- Support for a low contrast mode (we really haven't touched on this at all, but could be useful for some users).
- Dark mode
- Defined custom colors for: foreground-color, background-color, text-decoration-color, text-emphasis-color, border-color, outline-color, column-rule-color

I don't have a lot of guidance on how to do this, which is which I've included a bunch of research links as well as opening this as a meta issue.

While it should be a lower priority, I wouldn't dismiss inverted-colors out of hand. All the browsers can detect when forced-colors is active but Apple operating systems don't have a feature equivalent to Windows's contrast themes to activate it but do have an invert colors feature (only Firefox has a user setting to activate forced-colors at the browser level). And Safari is the only browser on iPhones and iPads.

But may not be a need for an inverted-colors media query, it would likely only be needed in cases where it's important for certain CSS colors to not be inverted.

You might find you also don't need a forced-colors media query, that defensive CSS techniques can avoid the need for specific rules for when forced-colors is active. The Sarah Higley link above is a good resource.

To be thorough, there's also prefers-reduced-transparency. "Reduce transparency" has broad support at the OS level but not yet at the browser level (not-Chrome browsers have concerns about fingerprinting). Day 103: the prefers-reduced-transparency media feature. If themes avoid using opacity or alpha channels in their colors, a media query for this is not needed.

Think Windows High Contrast Mode (WHCM) is being used as "high contrast" more consistently.

"Let's brainstorm where our default themes could be improved..."

Could we be specific and mention what themes we mean? Olivero, I see is marked obsolete. Back-end, front-end themes? Are any themes a priority to look at first?