So, if they laid it on a copier? How come the rest of the document, even to the left of the rounded edge (from the binding) is so seamless and of the same background as the paper the document is printed on. Last time I looked, the backstops on copiers are white backgrounds.
The background of the COLB is white. The backstop of the copier is white. The paper it is copied onto has the green security hash, so the green background is seamless.