Maybe it would be a good idea, to not only have a light-mode and a dark-mode for the GUI, but also kind of a “sepia”-mode with beige colors. Similar to the sepia-mode in the reader-view of some webbrowsers and other apps (e.g. in Safari’s reader-view of a webpage).
For some people the light-mode with many white is too bright, but the dark-mode is too dark for them. For these people (and all others who prefer a beige color-scheme) this would be a very welcomed addition.