What is Color Management? - Video Tech Explained 

Indeed!

You're seeing those dramatic differences because there is a mismatch between your output format and your display's format. Setting the output to Rec.709 and watching on a Rec.709 screen will look more or less the same as setting it to DCI-P3 and watching on a DCI-P3 screen. However, setting the output to DCI-P3 and watching on a Rec.709 screen or vice versa would not look correct. The image you see should only be treated as accurate if your output transform matches your display. Otherwise, it is not reliable.

@@VideoTechExplained Your explanation is very helpful for me but does that mean the only way to edit a rec.709 or srgb video on a wide-gamut monitor like the new MacBook is to set the output format to P3 to correctly show it on the wide-gamut screen for the color correcting process then change the output format to rec.709 or srgb for exporting?

@@malageb1 I'm not 100% familiar with Mac OS's implementation of the wide gamut display, but theoretically, yes. If the display is calibrated for P3 then the preview should also be P3. I would recommend double checking this with other Mac users, though

In Resolve you can apply the CST and then right click on the clip and export the grade as a LUT

That’s the point and goal of color management, to adjust various input to a single “lowest common denominator” output device. If using a wider gamut monitor you don’t see the color in the image to the full potential of that device but to the gamut limits of the output gamma which have been selected. The working space is simply a box which needs to be big enough 🎉to hold both the input color gamut and the output. By way of analogy if you ship fruit and need a box just big enough to either ship a pear, an apple or an orange. The baseline colorspace is CIELab which is based on the gamut of color the average human can perceive but some working spaces are even larger because some sensors record wavelengths in the IR and UV ranges we can’t see. On digital cameras “cut” filters are placed over the sensor it prevent the UV and IR from reaching it. Without a UV cut filter fabrics with UV brighteners are rendered lighter in color by the camera that we see then.