The two colours need not be black and grey; computer duotones can be created from a greyscale original in any two colours; tritones use three inks and quadtones four.

Incredible spoilerette/rumor regarding Kitsunegari (Fox Hunt) at the following URL (epi guide with Spoiler site)

Everyone's meeting at the new grill in town! And everyone's having a real good time! They're drinking frozen blue Margaritas. Munching on Cajun popcorn shrimp. Laughing with old friends and getting to know new ones.

I almost caught the critter, but it got away from me.