

I caught trouble the other day for saying this. Apparently there are themes for GNOME (even GTK4) that can mitigate the limited colour palette(s). Locked-in window layout choices are a different matter entirely, of course, but we can do something about the colour of them.
Black and white 80x25 BIOS text screen with the IBM PC ROM font, not unlike the MS-DOS it sought to replace.
Everything else is fluff on top of that, possibly occupying different graphics planes available in whatever hardware is available.
Yes, technically modern PCs and Linux have moved beyond that 80x25 screen for the most part, but its immediate descendant is still in use, often during boot, but also on Ctrl-Alt-F[1-6] on many distros.