Super Saturated Pixelation

[paroniusthedefiant]

On some of my 4k files, the colors are super saturated and pixelated, but ONLY in Jellyfin. When watching in VLC they look completely fine.
I am failry new to all his and not as techy as some of you.
The files are 4k BluRay MKV //  .4K.BluRay.x265

Screenshots of what the files look like:
https://imgur.com/a/rkgmDvQ

Thanks so much guys

[under1linen]

That's a classic HDR to SDR tone mapping problem; just go into your Jellyfin server's playback settings, enable hardware acceleration, and check the "Enable tone mapping" box to fix the weird colors.
Hope that helps.

[nyanmisaka]

Undersaturation is only seen in HDR files that are not tone mapped. In the picture it is oversaturated.

I'm guessing your SDR video was mistakenly marked as HDR video when it was encoded and tone mapping was applied.