Search the forum. How to bypass Gamma shifts and other color deviations has been discussed. Mucking around with color settings is of no use if your system is not calibrated and even then CoDecs will shift colors due to how their internals work, especially compressed ones like MPEG that use chroma-undersampling. when bad comes to worse, sending stuff to online services that do their own re-compression for bandwidth reasons and providing multiple streams will further increase the shift. That being said, getting wound up on specific RGB values is utterly pointless. The decoded value of a compressed CoDec by its nature will not necessarily end up being an exact match nor does sampling these values from an arbitrary player on an uncalibrated monitor have any relevance. That's simply not how video works and if the filter on this forum wouldn't remove it, I'd certainly know a few nice words for your client's insistance on "bluer than blue" logos or whatever. Been there, done that and ultimately it's nonsense. As long as it looks reasonable, no harm is done and if you have extreme shifts, only manual preemptive intervention with color corrections and adjustments can "fix" it.
Thanks bro. Much appreciated response.
Mylenium has a great answer on the Qt files themselves.
Also ... if the client is using the Quicktime player ... pity. That ... thing ... is S0 known for gamma issues and also for deciding for the viewer what sort of scale should be used.
On your machine, of course ... you can often go into the controls for your video card and set such things as whether players use their own settings for playback as far as 16-235, 16-255, 0-255, and gamma go ... or whether to use the calibrated stuff for you monitors instead. On any Nvidia-GPU'd system, you should be able to do that.
For my own, when I did set the 'over-ride', it made Qt a ton closer to viewing in PrPro ... but still not quite there. VLC tends to be very close to PrPro on my system.
But ... for clients viewing things through any player on their own computers ... good freaking luck. That is truly "out in the wild". It's totally analogous to say, judging someones' b-cast standard exports by playing them on a DVD player and TV rolled around a cart in a retirement home.
Thanks, all useful stuff to know.