Saruman was "the White" before Gandalf. But I do hope that by now he doesn't compare himself to a monster any more. So Gandalf would be more fitting.
Did he mention an open challenge? I of course remembering the Gatekeeper mentioning a confrontation.Well, the council brought that to themselves
It won't be Harry the White. It'll be Harry the Grey because he's going to form the Grey Council after "openly challeng[ing] the White Council to battle," as the Gatekeeper seemed to predict Harry would do. (TC).