I’m not sure. I’ve only noticed it on my TV and have even noticed it with content that I personally ripped from DVDs or Blurays and encoded to x265 or AV1. Since it only affects the TV apps I’m wondering if it isn’t a lack of support for some color space or something by the TV hardware because when I’m encoding I don’t usually change anything about the dimensions, color space, frame-rate, etc., just the codec and quality. If the video is 10 bit, I encode it as 10 bit. If it’s HDR, I pass that thru. I’ve checked with the mobile and desktop app and the web player on content the TVs had issues with and those same files played fine everywhere else, so it’s something specific to the LG and Roku apps for Plex.

I do my own ripping direct from disc and I’ve still seen it happen. So far it’s exclusive to the TV apps so I think it’s something to do with the lack of hardware support for certain things.

Plex has recently started applying a green filter to certain content.

The files Plex has a problem with work just fine in Jellyfin.