There has been a lot of recent discussion on the Adobe Premiere Pro forum about why folks working on newer i-macs are seeing pretty radically different color in the Premiere Pro program monitor compared to exported videos played back in QuickTimePlayer, vimeo, & YouTube. The reason they weren’t seeing the problem so much on their 2011 i-macs or their older MacBook Pros is because those screens are not as wide gamut as the new i-mac pro & mac book pro which now have what Apple is calling P3 color.
Here is the problem, since PP Pro doesn’t allow you to make the program monitor adjust for your wide gamut screen, what happens is that the Rec 709 space, being a relatively narrow color space, (like sRGB), is inappropriately mapped to the wide gamut screen. As you can see in Photoshop, if you have an sRGB image file but you ASSIGN a wide gamut profile, such as Adobe RGB, you will see that the image becomes very saturated. This is essentially what is happening in Premiere Pro on your new i-mac.
This is a huge fail on Adobe’s part. Apple’s Final Cut Pro is color managed, so your footage looks correct as you are working on it. Adobe can fix this easily, why they don’t is a mystery. Imagine if Adobe Photoshop wasn’t color managed. How much fun would that be?
To make matters worse, it isn’t possible to make your new i-mac emulate sRGB, so if you are using Adobe Premiere Pro, you must have a second monitor capable of emulating sRGB or rec.709 so you can color grade accurately.
Some people have been using an adjustment layer that sits on top of the Premiere Pro timeline that attempts to adjust the color to emulate what you would see on a screen that is emulating sRGB or rec.709. While this might get you sort of in the ballpark, it seems unlikely to be accurate enough to count on for commercial color grading.
When this topic comes up in the Premiere Pro forums, the recommendation from Adobe is that if you are working commercially, you should have a broadcast monitor to display the program monitor. While this is true, it isn’t particularly welcome news to video professionals who bought new 5K i-macs thinking that they would be an all-in-one solution to commercial postproduction. Besides, real broadcast monitors are pretty expensive. Eizo makes a great one for around $5700.00. That’s more than the entry-level i-mac pro. Fortunately, you can get a workable solution for much less by using a second monitor that can actually emulate sRGB or Rec.709. I have an older Eizo that fits the bill. A better solution might be something like the NEC Multisync PA272W.
IMHO, every video editor should be working on at least 2 screens, so the practical work-around while we wait for Adobe to come to their senses, is to have a second screen which would be actually profiled to sRGB or Rec.709 and that is where you should put the program monitor panel.
You should keep your i-mac screen set to the i-mac profile, or better yet, profile is to something like D65, 120 cd/m2, and native gamma. That way, your web browsers will look good, & your playback with Quick Time will look good, and so will YouTube and vimeo. VLC, will look over saturated on the i-mac screen since it has the same problem as Premiere Pro, namely being stuck in Rec 709, but it will look good on the second screen that is emulating sRGB. This may not be as belt and suspenders a solution as a dedicated broadcast monitor, but at least your clients won’t question your abilities.
I hope this helps!