That's Italian, rainbow-haired Sunbeam. Very rare.
It's true that some people call her "Sunstone", but there's really nothing linking her to Moonstone specifically, other than the rainbow hair. So she might as well be called "Skybeamer" or "SunWindy", lol. Her body is aqua blue like "normal Sunbeam", not powder blue like Moonstone. (I used to own one, so I compared, lol.)