It took me more than an hour to figure out what the heck he was doing, but I persisted because I felt this could be a very important tool to master. I used his method on the following picture which I didn't get to my liking color-wise. I used the method of the video followed by a Brightness/Contrast layer and a warming Photo Filter layer where some light signs are masked out to retain their real color. I'm not sure I'm there yet but it looks promising. Thomas showed it for interiors where you often get different color temperatures and casts in shadows/midtones/highlights and I'm sure it'll work very well there.