Uxie, Mesprit and Azelf; the Lake Trio of Sinnoh.
EDIT: Image updated. The gems on their heads are all blue in the normal 4-color palettes, like their bodies, while their shiny 4-color palettes have their bodies and gems yellow.
EDIT: Image updated. The gems on their heads are all blue in the normal 4-color palettes, like their bodies, while their shiny 4-color palettes have their bodies and gems yellow.