Additional Preview features - split screen, ability to adjust colours in player window (view only) & Other colour reference features

[PeteDraper]

Some control of colour is needed in the Preview player:

the ability to tweak "looks" - even basic controls like gamma, gain, saturation etc would be very useful in shot reviews, even if we're working with MP4s

histogram display, scopes etc

Being able to view separate R G & B channels

Also, while the side by side and % transparency is good, being able to A/B swipe between two sources is also required esp for matte / Roto edge fidelity analysis

Se DJV2 for an example of the above.