Light is currently default for two reasons

1. To allow the user to explicitly opt in and not be surprised when dark mode applies to Wikipedia when they didn't want it
2. There are still many accessibility issues with dark mode, and it is important readers are aware of that when opting in (hence the word "beta")

Removing the word beta would be a prerequisite for this in my opinion.

https://www.mediawiki.org/wiki/Reading/Web/Accessibility_for_reading/Frequently_asked_questions#Will_dark_mode_be_the_default_setting?

Thank you so much for your answer Jon, please feel free to point out to the specific accessibility issues to me so I can check if I can be helpful and am able to resolve easier ones maybe and while I surely understand beforehand many important issues already exists, I just wish initially just my local wiki (fa‍‍wiki) that I surf everyday using the dark mode and am improving different bits of it with dark mode can get this following OS option as the default option specially as I believe it's expected for whose that have the OS setting for dark mode to see websites per the OS settings (say like e.g. https://www.instagram.com that gets dark mode based on OS setting just right from the start) but that's just a wish and I understand your concern as well.

Change #1123650 had a related patch set uploaded (by Ebrahim; author: Ebrahim):

[operations/mediawiki-config@master] Make 'automatic' default vector theme option

https://gerrit.wikimedia.org/r/1123650

Thank you so much for giving me the roadmap @Jdlrobson-WMF

Empty the associated message to remove the beta tag https://en.wikipedia.org/wiki/MediaWiki:Vector-night-mode-beta-tag

Done, locally https://fa.wikipedia.org/wiki/مدیاویکی:Vector-night-mode-beta-tag

Add the following to configuration:

https://gerrit.wikimedia.org/r/1123650

There are still many accessibility issues with dark mode

All the reported issues at https://www.mediawiki.org/wiki/Reading/Web/Accessibility_for_reading/Reporting/fa.wikipedia.org are resolved AFAICS

I've also asked it on the local technical village pump https://w.wiki/DEwo whether they have any other comment on the change, we can wait some days for them as well if you wish so.

Change #1123650 abandoned by Ebrahim:

[operations/mediawiki-config@master] Make 'automatic' default vector theme option in fawiki

https://gerrit.wikimedia.org/r/1123650

@JScherer-WMF @ovasileva this poses twos question:

• given what we saw with roll out (interference with browser extensions/people unexpectedly getting dark mode) would we ever re-consider making "automatic" the default
• At what point do we remove the "(beta)" status from dark mode feature?

re: the open questions from @Jdlrobson-WMF, I started a discussion on the dark mode gadget page to get feedback from the community on what their thoughts are with regards to blockers.

Discussion: Changing Default Color to Automatic