If anyone is looking for the mpv core with a GUI on macOS, take a look at IINA
https://github.com/iina/iinaIINA has issues with color space conversions. I've heard that the specific issue is that it always (incorrectly) assumes a BT601 matrix for all videos, though I haven't verified it myself and cannot really right now. (I did verify its colors differing from stock mpv before writing this comment, though.)
Various mpv wrappers exists, but for reasons like these stock mpv is the only fully reliable version.