Custom Default Light and Dark themes for instances

[comfy-v]

In order to customize a community, theming is important. By default, lemmy-ui has a light and dark theme, chosen depending on the user browser's preference. However, if an instance wants to change theme, they can only chose a single theme for either light and dark modes.

Consider an example on lemmygrad.ml, which has a red variant of both litely and darkly. However, they are forced to select one of them (they chose red-litely) causing a user used to one of the modes to note their discomfort.

Describe the solution you'd like

I do not administrate an instance or have a test, but I assume there is a dropdown option for an administrator to select the instance's default theme. I would like there to be two options, one for a default light theme and one for a default dark theme.

[Nutomic]

I believe this already works. If you set theme "browser default" under /admin, users will get the light/dark theme based on browser preferences. At the same time, custom themes are given preference over builtin themes. So if you add your custom themes with the same filenames (darkly.css and litely.css) it should work like you describe. However, this will make it impossible to use the original darkly/litely themes, so it could be improved.

[dessalines]

I do see the value in adding light and dark versions when using a custom default theme I spose. Although this might be overkill... not sure.

[Artoria2e5]

It would be great to have a paired theme switch where you define which theme is used for light and which one is for dark, preferably on a per-user basis. Maybe split the theme section into two and let the user set what to use when light and dark separately; there can always be a dummy option to say "use whatever light is using" to turn off the switch.

I would love to use such a feature when a pair of high-contrast themes become available.