Prior to taking a screenshot from the Cutscene editor you could set the background from teal to black, then do Color (Black) To Alpha or whichever the background could be Teal color to Alpha but it should be based on the general colors, if it appears semi-transparent you could further change 'Levels' of the alpha channel to make the remaining model not transparent at all. Then greyscale, increase contrast/brightness, compare with some of the existing wireframes.
That is actually a good idea, I may have to do such things in the future as well!
New to the cutscene editor. Can't find how to change the background such as you said, where do I set this?