Is "white time" (black digits on white background) when Toki time travels and "black time" (white digits on black background) when Fumi destroys the world and resets time a few hours?
EDIT:
Actually, no, upon further reflection, I think "white time" is the new starting point for any time loop, after the previous time loop had been resolved satisfactorily.
This si actually amazing, gives me EVA/Devilman Crybaby/etc vibes with the whole “small scale premise with huge and very important consequences” plus all the mystery around it.
Thank you for translating!