plasma tech was not designed to do o blacks, oled yesThese screens were able to go pure black from the beginning. Over time, they're over 10 years old now, some developed a red push.
You could get into the service menu and alter the settings to fix this, which I did. All the information is in this thread still from various members that have done it, including comparisons to Oled.
I still have mine, but it's in spare room as I've upgraded to oled.