@ edgerobbie

Can you clarify what you want to do?
Essentially, a Virtual Set Input is blank or transparent with layers applied to it, so there is nothing to colour key from the original Input or base layer therein.
Background images or sets are basically added as layers in the config file and you generally do not have access to them, but they are still layers on the Input.
If there is something that you want to key out on those images, you would have to add it as an Input in vMix first and then use the colour key on the actual Input and then add it as a layer to your set, just like removing the Green screen of the Talent layer.

I hope that makes sense.



Ice