I find this entire subject interesting. It is my understanding that the 1953 color gamut standard was never exploited even to this day. While DCI P3 comes close, Rec. 2020 exceeds the 1953 color gamut. I see a clear difference in NTSC 1953 green on my 15GP22 compared to my modern displays.
This Power Point by ISF (Imaging Science Foundation) address the subject well.
https://visions4netjournal.com/wp-co...-2017-33.3.pdf