Grace noticed that Charles' and Richard's hair was increasingly becoming redder and redder, while freckles began to appear on their faces. It seemed as if the people who had paired up, according to what color they wore, had acquired the same (or nearly the same) ethnic background. And from the look of it, Charles and Richard (and most likely also herself) were acquiring an Irish background.
She briefly wondered whether or not they would have Irish accents, when her attention was suddenly diverted towards one of the couples nearby.