there's a mod for it and iirc also as a hidden setting, does neither work on the forma?
I'm fine reading white/gray on black on other devices (smartphone with oled screen), but with eInk there tends to be much stronger ghosting this way, so either you need more screen refreshes or just stick to the black-on-white it was apparently made for...
Now if only I could get rid of the black borders so only text is black... but white/grey shelled readers went out of fashion apparently
