From what I've seen, it effects Disruption? Orange flash makes it ignore block, but it doesn't hit otherwise, blue flash hits otherwise from what I've come to understand. Edit: Was wrong, it's just the standard undertale thing of making the attack hit moving or non moving targets depending on orange or blue. I think I might've just aimed low when targeting the blocking opponent, so that might be where I came in wrong

Eye flash prepares a special attack called disruption. Blue cannot hit stationary targets, so it only hits opponents in motion. Orange is the opposite, where it only hits stationary targets and can't hit moving targets.

Orange also does significantly more damage then blue. This is likely meant to balance the move for actual YOMI combat, I mean just think about how often you stand still in this game, I'd say the higher damage turns the orange disruption into a sort of exponential risk grate reward type deal. It can also work to punish stationery zoners.

Along with everything else that's been said, you can STACK disruption charges. So you could do Eye Flash Blue, then Eye Flash Orange and disruption will be set to orange, then once used it'll be blue disruption. It has its niche uses.

use disruption, the both orange and blue work the way that they do in the game. (Orange:
not moving=hit,blue:moving=hit)