[Stu Lockley]

Was sent this answer

premiere isn’t color managed. it will ignore any display calibration unless its the native rec. 709 0-255 and that’s because your “calibration” will match premiere’s internal color engine interpretation similar to AE’s pass-through if view-simulate turned off.
premiere won’t understand P3 but there is a workaround. you can use LUT transforms to match your monitor’s P3 color profile then load them into lumetri technical.

P3 to Rec. 709 x64 iridas cube
CreativeCOW

or you can make your own transform lut with
https://sellfy.com/p/aQ1y/
or with
DisplayCAL (formerly known as dispcalGUI)—Open Source Display Calibration and Characterization powered by ArgyllCMS

fixmyyoutube
64 cube iridas lut for burning in darker 16-235 from 0-255 for youtube upload. it darkens image, then youtube re-lightens again.
fixmyyoutube – Creative COW

[Stu Lockley]

I too have the same problem on my 5K imac. However I think I have resolved the issue, although the solution is not the best with out a using another NLE.

IF you open premiere, your export in QT and VLC, even youtube, make all 4 windows visible. Then open your colour profile window in system prefs and start flicking through the different profiles (apple rgb, rec 709 etc). You will see QT and youtube change their look inline with the profiles. however Premiere and VLC do not change a bit, they flash the profile and then revert back some kind of default.

Now do the same process with davinci resolve, as you flick through the profiles, resolve will change in line with qt & youtube. (note, i had to click on the resolve app before the profile updated).

This shows that now matter how you have calibrated your 5k imac monitor, premiere ignores it. So you are never grading to any colour standard. Do the same in resolve and the results match.

This is very bad for my projects as I can’t colour grade in davinci due to the level the projects are at with AE worked linked between the apps.
https://vimeo.com/221050047