I followed the instructions in the Change a device’s color profile using ColorSync Utility on Mac Apple Support document and set the color profile for my internal display to the LG profile in my home directory.I copied from /Library/ColorSync/Profiles/Displays/ the color profile for my external Apple/LG monitor into my home directory.IINA loaded wrong ICC After disabling the preference did you restart I tried to reproduce the issue with IINA ignoring a custom ICC profile and failed.Disabling 'Load ICC profile' did not work.I'm not familiar with the changes made in this area. The current suspect is a change in behavior of the 'Load ICC profile' preference under IINA/Preferences in the Video/Audio section. So this issue requires further investigation in my opinion. Due to this issue I tested screenshots of an HDR video and ended up with an overexposed image with washed out areas. There are definitely issues with screenshots. I'm thinking IINA should add a preference for enabling this. The inspector window will also show the 'Color Profile'.

In Preview click 'Show Inspector' under the Tools menu. In Finder right click on the screenshot file and select 'Get Info'. Turning that option on will add an ICC color profile to the screenshot. Tag screenshots with the appropriate colorspace. Of particular interest is screenshot-tag-colorspace:

The ones IINA does not provide support for can be added in IINA/Preferences/Advanced in the 'Additional mpv options' section. Many other screenshot options are available in mpv. When you change screenshot preferences in IINA/Preferences/General IINA is merely configuring mpv's screenshot feature with those settings. That library is also used to create screenshots. For video playback IINA uses a library from the mpv project. I'm not familiar with those changes, so I can't say for sure. There have been changes to the handling of ICC profiles as a part of the HDR work.

Iina vs quicktime