The thick plottens... It seems likely that Marietta BSed about her investigation and Teresse's roses were the only ones to change color. As to what that signifies, SHE seems to know and, uh, appears to think it important enough to do a disappearing act with Teresse. What she thinks she'll gain...
Well I think that's the first time I've seen in a manga or an anime someone realizing that when they travel to Hawaii they're in fact entering the US of A. Usually they seem to treat it as if they were going to a country called Hawaii.
@Ariria I don't know what titles that guy has, but in feudalism it is entirely possible to possess multiple titles. If you were in charge of a tract of land (which most importantly gave you tax income) it was denoted with a title and you were considered a noble. Multiple claims meant multiple...