My, that's subtle.

I can't imagine this being functional for any person with limited vision. @Volker_E, do you have the set of low-vision glasses at your desk, so that people in the office can see how awkward that is?

@Whatamidoing-WMF That is actually true, I've got some. :) Although that change came from @TheDJ, who I haven't seen in the new office yet. In his defense, he has introduced 'active' state of Wikieditor toobar tools at all. Wikieditor didn't know concept for such state before!
Compare for example 'bold' button, there's no active state.

One way out were to give the toolbar more of a unified appearance as in T174119. But that would probably need more community consultation to move forward…

i'll slap on whatever css needed if someone hands me a design that isn't 'change all the things'. ;)

P.S. Toggle state was the result of work from: T198781: Add toggle/state buttons to WikiEditor

Visually it's simply the hover/pressed state of any of the other buttons, right now.

*tumbleweed*

Is there some hackathon or similar event where we can ask people to attend to this?

Let's make the full toolbar VE/OOUI like. Design team designed it to work with accessibility and usability focus. There's even a patch out by @Esanders in https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/WikiEditor/+/509882/

The only concern was to not make it too VE-like to provide a clearer indication of being at different, deprecated product. But I don't think that's a great argument, nor is the current visual presentation in any ways a better user outcome. The background and the colors should be taken out of this concern.