CF.Lumen works at the kernel level by installing a kernel driver which actually changes the screen's colour output rather than being an overlay, but it requires root. Can't really fault apps like Twilight for not being able to work around limitations.
I used twilight for a while, but I actually got rid of it because I couldn't get rid of the watch portion of the app or turn it off.
I suppose I can see why some people might want it on the TV, but I certainly would not. If I'm watching something, I really don't want a reddish tinge laid over it. (I always had exceptions set on my phone for media apps.)