I only vaguely remember those from early childhood as the stations went to different formats quickly afterwards to the color bars.
I used to get up on Saturdays mornings very early because the first thing that came on was the Creature Feature. I would set the TV right, get some cereal and juice and curl up with the dog ready for Boris or Lon or Godzilla.
You could calibrate your tv picture tube to a black and white test pattern.
Few people ever color calibrate to the color test patterns.
But I got one of David Lynch’s self-released DVDs and he had several screens of calibration settings so you could get your equipment close to the calibration he intended.
Criterion laserdiscs used to also come with color calibration test patterns at the end of the disc (I think a green contrast/sharpness screen as well as the color bars).