>>106921793
Color, but the easier to see is just brightness. Something like a lightning bolt in a game will be multiple times brighter (OLEDs generally have 1000nits on small areas) than in SDR.

There is simply no way to not notice, the effect is strong enough to make a very noticeable difference even just looking around your room instead of at your screen because it will light things up 5x what SDR does.