I’m not sure if something like this has already been mentioned, but I’ve been having issues color matching images to 4K HDR sources. The colors are not an exact match and end up looking pale. I had the color spaces set to 250, smoothing parameter to 0.01, and the fast processing mode turned off
Test Image
Reference Image
You cannot just match HDR sources. For one you need the images to be 16 bit. Secondly, you need to add HDR meta data to your source.