Remember when you'd look at a monochorome green CRT for a while then look at a blackboard with white chalk - but all the chalk looked pink for a while?

Animating in the 90s and 00s people still used CRTs and flat screens then had lousy colour. There were many problems with CRTs including unreliable colour. A special small "monitor" with accurate calibrated colours could cost $5k. We'd all huddle around the monitor to analyze our colour work.

On a Kraft Mac & Cheese / Crayola crossover spot we animated little kids. Our diverse hero kid, "Pablo", had to be tan but the director kept having fights with the lighting guys about what "tan" is as it kept drifting between orange-ish and green-ish shades, difficult to nail down the correct shade. Plus all things were relative within the frame and just colour picking a sample was not an option.

Also, I was told that CRTs cannot produce "aqua" or "turquoise" or something like that, though I never bothered to look it up until now. Not much out there on it. I wonder if it was just a weird rumour.

On CRTs we also had to avoid moiré patterns and fine 1px horizontal lines that used to "sing" or vibrate due to the 60hz half frame interlacing for the 30fps. The solution for singing lines: blur them a bit.

https://en.wikipedia.org/wiki/Cathode-ray_tube

https://en.wikipedia.org/wiki/Moir%C3%A9_pattern