What's wrong with Kari?

Kari has been affected by what many in Neopia are calling the grey curse. However, no one really knows anything about it so we can't be sure if it's a curse, an aliment, or what! All we know is that it is somehow affecting Neopians all over the lands and nothing seems to be able to cure it. Things such as Paint Brushes and Morphing Potions seem to have no effect. Not even Naia's Rainbow Fountain can change one back from being grey!