Hair color changing without reason or warning

[Ingemar]

Have you ever seen an anime in which a character changes hair color without reason or warning? The only time I can think of something like this is in Xenogears:

[spoiler=Krelian]His hair changes from blue to blonde. I suppose since he's over 500 years his hair color could fade or he could just tire of his hair color so he dyed it. But they never give an explanation of how or why his hair changes color.[/spoiler]

[Debitt]

Kantarou's hair is mutable...blue/green-ish in the anime, and brown or blue/greenish in the manga...

I'm still not sure what color to call Haruka's hair, either...

[Bobtheduck]

Schala in Chrono Trigger has blue hair... In CC, she has Blond Hair... It's not exactly anime...