Would you like to be associated with anything as unsavory-sounding as chromatic aberration? Surely not! All aberrations aside, where they usually reside, the Purple moniker has its origin from the purplish iridescent hue that sometimes appears on the bird's breast, especially after a good thrashing by bully-birds, which firmly reside on the fringes of my imagination like shells of chromatic aberration on a crisp morning. I've never seen this purple mantle on the two occasions that I've seen these sandpipers but the feature may only be present later in the season, when ice and snow are present, when the bird is entrenched within its non-breeding cycle and probably cold and miserable, feeling and looking a little blue but appearing purple due to that chromatic aberration and all that purple water. You think me nuts, I wager. Thou hast exceptional perspicacity m'lady. Maybe the purple is really there, but subtle and we have gotten so used to outrageous LED pixels in vibrant colour that we have lost our ability to discern the nuances found in nature.