I think it's White (while the boy is called Black), considering how the protagonists of the games were often named after the title (except Diamond, Pearl, and Platinum). Hell, I wouldn't care changing the tags, do it early and it's not a big deal.
Her default name in the games is Touko. The boy is Touya. But really, there isn't much of a precedent for the game protags being named after the game's color/metal. The only one who's actually confirmed to be like that is Red since he appears as a non-protagonist with a name. Gold and Leaf are kind of fan names just based on them being the first defaults, Kris was confirmed on the back of the Crystal box and everyone else has a real name.