These days, most of us use devices with AMOLED screens. That kickstarted the trend of having applications and websites with the option to have a dark themed presentation.
I do believe these forums would benefit from such an option in the future.
There are countless configurations that can be applied, however, I think that having three different presets is the best one: white (the current one), an intermediate option in a dark shade of gray (no, not those shades of gray), and a third option where the page turns pitch black.
I am aware you can achieve something close to this with an extension for your browser, Dark Reader, for example. However, I always believe that a native configuration is the best one, avoiding incompatibilities with inverted colors.
Perhaps Nothing can associate this choice with your profile, syncing it across the multiple devices you use to access the forums. It could make the reading easier on the eyes, be it on the screen of your portable device while saving battery life, or even if you are using a browser on your computer.
Even if Nothing is thinking about developing a Community App, before that becomes a reality, I think that having this solution could ease the eyestrain while making the forums look cooler. And if you prefer browsing them as they are, you would always have the “default” option.
