Exported video looks totally different on YouTube than in premiere or VLC

You need to learn a ton about color spaces, profiles & such ... the problem is your Mac is using Apple's "P3-Display" color space. It's a new creation used only in the new Mac P3 monitors, and nowhere else on the planet.

Nearly all production video including broadcast TV and actually movies is created in Rec.709. The specs are video sRGB, Rec.709, gamma 2.4, white point D65, brightness of 100 nits.

For movies, it's often created in that then exported into P3 Cinema or P3 Theater for distribution. Some productions even start post in a P3 space. Those have the slightly wider P3 color gamut, use slightly lower D- white points, and gamma of 2.6, and really MUST be viewed in dark rooms or the shadow areas are way too dark.

The new Apple P3-Display standard uses the wider-gamut P3 color space, but rather than the white points of the two previous P3 standards, it uses the same white point as video sRGB, which is nice. That is D65. They don't give a brightness, but then, we don't get one in HDR, so we all will have to adapt to that soon enough anyway.

The gamma is ... odd. The standard lists  the gamma only as "sRGB". When you look up gamma for sRGB, it's ... three different gammas at three different points in the curve, with a complex transformation calculation to smooth the differences, and is roughly similar to but not the same as 2.2.

When the Adobe color engineers tried to reverse engineer what is actually the "working" gamma, they set out to make a transform LUT with an inverse LUT to send something from Rec.709 to a "perceptual match" in the typical "stock" P3 Mac monitor, then use the inverse matching LUT to see if they could get back to exactly the same values in Rec.709. What they found in reality was a need to use a "scene referred LUT" of 1.96.

Lifting the shadows ... dramatically ... as happens when going from gamma 2.4 to 1.96 is one of the problems you're having. The other is the non-correct mapping of video sRGB color space to the wider Mac P3 color space.

Color Engineer Francis Crossman and Carolyn Sears wrote up a document about this available on this forum, and include the links to the two LUTs that were designed for this.

But note ... the issue is that your Mac uses a color space that is used ONLY by other new Macs with P3 monitors. So if you make specifically for that space, the gamma and colors will be off quite a ways on the vast majority of screens out there. Mac also seems to use an internal system which tries to get a perceptual match for some outside media in some forms, no one seems to know how it works, or why it seems to work in some ways and times but not with other media.

Yea, it's a bit of a mess. There are no standards for color and display currently being recognized and used the same by all apps, OS, and devices. What most colorists do is simply work to the Rec.709 standard, and let it go. At least it looks the same as other Rec.709 professionally produced material on the majority of screens out there.

The option to 'enable display color management' in the Preference panel may help you ... but it's NOT the same as using a calibrated profiled display setup. It attempts to get a perceptual match ... to the ICC profile used in the OS for the monitor. It means you may get a more "correct" view of your material within Pr than otherwise with the neat but odd monitor you're using.

But test it first. And see what your stuff looks like on monitors that are NOT Mac P3 monitors also. And read through Francis and Carolyn's document ... also, I'll have a free tutorial on the MixingLIght website within a few days on the complete color management "system" of Premiere, which has never actually been fully documented before. TONS of work have gone into that, hours of time with Francis via phone, computer screen share and in person, countless emails & texts. Tremendous support from the Premiere Pro team under Principal Product Manager Patrick Palmer.

Neil

"Why does my footage look darker in Premiere?" Color Q&A