Currently most monitors use 16bits for colour (65,536 different possible colours).

The human eye can see about 10,000,000.

HDR / True colour is 24bits, 16,777,216 colour variations, which is more than what humans can see.

You should care because it means images on your device will look true to life, especially as screens get brighter materials like gold will look much nicer.

I don’t think they patched them all

https://www.wikipedia.org/wiki/Jammu_and_Kashmir_(princely_state)