There have been several instances of feedback asking for a "dark version" (dark background, light text). I don't know if vector tires the eyesight more than monobook or it's simply that they now have a way to ask for it, but the petition was higher than I expected.
Probably more appropiate to provide as an alternate stylesheet than a separate skin, though. I wouldn't be surprised if some wikipedian already designed it.
http://es.wikipedia.org/w/index.php?title=Wikipedia:Comentarios_sobre_experiencia_de_usuario&diff=37939214&oldid=37938825
http://es.wikipedia.org/w/index.php?title=Wikipedia:Comentarios_sobre_experiencia_de_usuario&diff=38075969&oldid=38073560
http://es.wikipedia.org/w/index.php?title=Wikipedia:Comentarios_sobre_experiencia_de_usuario&diff=38246256&oldid=38216451
== Related projects ==
[[ https://en.wikipedia.org/wiki/User:Volker_E._(WMF)/dark-mode | WMF-developed dark-mode userscript ]] usable since October 2019, showing complementer colors with the css rule `transform: invert(1)`and specific cases fine-tuned for legibility.
[[ https://phabricator.wikimedia.org/project/view/4006/ | Dark-Mode project ]] to implement this in MediaWiki.
{T122924}
[[ https://www.mediawiki.org/wiki/User:Aron_Manning/Skin_themes | Skin themes ]] – dark and gray themes for Timeless and Vector skins. Custom color palette, similar to discord's colors. Experimental volunteer project: there is some content that's hard to read with it.
[[ https://meta.wikimedia.org/wiki/Community_Wishlist_Survey_2019/Reading/Night_mode | Wishlist Survey: Night mode ]]
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**Version**: 1.21.x
**Severity**: enhancement