Mjpegstreamer image overdriven - qv4l2 image totally fine

Camera model
Raspi Cam HQ with Pentax Lens

What is the problem?
Output of mjpegstreamer is overdriven. Unable to find a well balanced and crisp parameter set.

What did you already try to solve it?
If I compare the image that mjpegstreamer outputs to the picture that qv4l2 provides and the latter one is way better. The mjpegstreamer output is kind of overdriven, colors fade and highlights are intense. I tried like any single parameter but cannot find out how I will get the same crisp and clear image from mjpegstreamer as from qv4l2.

Logs (/var/log/webcamd.log, syslog, dmesg, ... no logs, no support)
Here are some snippets of things that I tried in /boot/octopi.txt:

#camera_raspi_options="-x 1920 -y 1080 -fps 10 -sh 25 -ex off -awb fluorescent -quality 100"
#camera_raspi_options="-x 1920 -y 1080 -fps 10 -ex off -awb cloudshade -quality 100 -br 75 -co 60 -sh 25"
#camera_raspi_options="-x 1920 -y 1080 -fps 10 -ev -ex auto -awb fluorescent -quality 100"
camera_raspi_options="-x 1920 -y 1080"

I also include an image comparing the both. The left one is from mjpegstreamer (in this case without any parameters, but all the different above mentioned setups effect in kind of similar behaviour, though brightness and contrast of course have effect, but still: totally overdriven...)

I can provide other logs, too, but dont see sense in dmesg or the like since basically everything works technically...

Additional information about your setup (OctoPrint version, OctoPi version, ...)
OctoPrint 1.4.0 running on OctoPi 0.18.0 on raspi4

I need a clue from a cam-Pro. Maybe its also a problem of understanding: Is qv4l2 totally different than what mjpegstreamer? And: I appologize if this topic is solved already, in that case I am to blame for being unable to give the correct words to the search ...
Thank you for any idea...

I was about to say test the -ex and -awb settings but you already did that.

v4l2-ctl -d /dev/video0 --list-ctrls lists most of default values used. I hope that helps