I thought maybe you had another copy to compare it to.
I wish!
If all known copies look like this, there's a chance they were printed like that, yep. We won't know for sure unless another copy in different condition appears.
I just find odd that if all the other pieces from the promotional campaign use such bold coloring, the insert looks so "washed" (for lack of a better term).
Maybe it has to do with the printing process, as stone lithography was used for one sheets (wich keep their bold colors) but the insert and lobby cards were offset-printed, and maybe those inks aged differently?
The dust-jacket of the photoplay book is a good example of what I mean. This 2 copies were auctioned by Heritage, and as can be seen, light has affected one more than the other
