Equipment: Rainbow in the Office

Like the movies and TV before it, the copying-machine industry has been eager to move from a purely black-and-white technology into color reproduction. It has long been known that such mammoths as Xerox, RCA and Po laroid were entered in the race. Yet last week, in a preview at Manhattan's Roosevelt Hotel, St. Paul-based 3M Co. (formerly Minnesota Mining and Manufacturing) was the first to break from the gate. When the gold curtains parted on the stage of the hotel ballroom, 3M proudly revealed two prototypes of a copying machine that can faithfully reproduce in color.

A distant second to...