The idea of FRC is to quickly switch back and forth between two nearly identical colors to display additional colors not available in the display's color palette. Since color switching rates on LCD displays is not instantaneous, it gives the appearance of a color in between those two nearly identical colors.
I found this video on YouTube (https://www.youtube.com/watch?v=j5lrZVvBS4s
that purports to record FRC in action. On the left you'll see an ever-so-slight change in colors. This slight change makes sense, because even with a 6-bit color depth we're talking about 262,144 colors - which is quite a lot.
What I'm struggling with is how such a tiny change can trigger symptoms, or even be visible. My eyesight is very sharp and I'm terribly sensitive to most common visual stressors, but I can't make sense of this.
Help me understand what it is about color dithering that makes it so problematic.