After angry cries of "Outrage!" from architecture professors, the Illinois Institute of Technology (IIT) has removed a costly, new, rainbow-colored entrance canopy from the university's library because it clashed with the building's original severely styled modern design.

The canopy, a 32-by-12-foot steel beam addition that an IIT architecture student described as "a giant tinkertoy," was installed last week at a cost of about $250,000.

But when startled architecture professors and senior IIT administrators spied the brightly colored addition to their just-renovated library, they demanded its removal.

"Nobody from our school of architecture was ever consulted," declared John Root, head of the IIT committee that oversaw extensive interior renovations just being completed at the library. A black-tie rededication ceremony is scheduled for Friday evening to mark the completion of two years of work and the reopening of the library.

Like most of the IIT buildings, the two-story library, built of black steel and tan brick, was designed in the austere style of Ludwig Mies van der Rohe, whose name is synonymous with the modern design edict that "form follows function."

Today, while workers paint the new, curved railings around the sunken library plaza and gardeners line up rows of ornamental plants, metal bolts and scrapes across the concrete are the only clues that an entrance canopy ever hung here.

Taking the ill-fated canopy down was "a wise decision," says Chicago architect Walter Netsch, who built the library as "a homage to Mies," back in 1962. He said today that he consciously set out to bring his design into conformity with "the Mies vocabulary." "I did a lot of research. I was going to try not to insult the grand old man."

Netsch applauded the decision to tear down the heretical canopy, but criticized IIT for allowing it to be erected at all. "There seems to be a left hand and a right hand, and an institution that is forgetting its heritage."

The rainbow-colored canopy was perceived by many on campus as a direct, Post-Modernist attack on the Mies style.

A quartet of students sitting and sketching on a green lawn jointly condemned the canopy. "It's just another attempt for the Post-Modernists to attack Mies, because they all hate his style," said Scott Schaeffer, a first-year architecture student.

His friends agreed.

"They should let Mies stand, but they want to be different," said senior design major Steven Saraceno.

"It didn't match the campus," said John Jesse, a first-year architecture student.

"This campus is totally Mies' design," said Bill Earle, also a first-year architecture student.

Faculty members were also displeased. George Schipporeit, dean of the college and chairman of the IIT architecture department, described the chain of events leading to the completion and removal of the canopy as a "comedy of whatever, I'm not saying error . . . It's very unfortunate."

Only among architects can esthetic arguments cause cranes to be called in for demolition work. "If you had taken that canopy and done a complete building in that manner, that would have been different than putting some Mickey Mouse thing in front of a building that is already designated a landmark," said IIT associate professor of architecture David Sharpe. "Why would you go in and make a mockery of what's there?"

The man responsible for the controversial addition, Robert Nevel, said in published reports he intended no disrespect toward Mies. He offered to paint his project black, but was told by university officials that it could not stay up. Attempts to reach Nevel were unsuccessful.

John Root says there is confusion about the series of events that led to the construction and removal of Nevel's short-lived work. "To my knowledge, there aren't any renderings that show the colors." He added that it is possible such renderings are in the possession of buildings and grounds chief Don Mehlenbacher, who is expected back from vacation this weekend.

"The canopy started going up just after Labor Day, and I first saw it the Tuesday after. I was shocked," Root said.

The radically designed State of Illinois Center, in Chicago's Loop, was also the subject of architectural controversy when it was dedicated this spring, but nobody tried to tear it down. The pink and blue building was designed by Helmut Jahn. Summing up the style war on his campus, Root said, "Nevel looks like he wants to become Helmut Jahn overnight."