>>13903238>Were these because of the pokemon seizuresMy best guess is because towards the tail end of the 1990s, with early digital techniques seeping its way into animation more and more, there was a sudden increase in anime with rapid flashing colors, so there was an effort to warn children to take care of their eyes.
It's also the reason why TV anime even today darkens the screen during very flashy scenes, only to be fixed in the BDs.
Some of the stuff in GaoGaiGar raped my eyes and gave me headaches.
