CHICAGO (AP) _ Workmen completing renovations on a library at the Illinois Institute of Technology added the finishing touch, a $330,000 multicolored metal canopy over the doorway. Then they tore it down again the same day.

Top institute officials apparently had not seen plans for the red, yellow, blue and green canopy and decided it was out of place on the black steel-and- glass library, said architect Robert Nevel, 31.

The canopy was removed Tuesday, the same day the 32-by-12-foot structure, suspended from the roof by red cables, was completed.

Officials felt it was ''disrespectful'' to the work of architect Ludwig Mies van der Rohe, whose style dominates the 120-acre campus, Nevel said.

The late architect's style is described by critics as ''austere'' and ''somber.'' Nevel said his designs, including the multicolored canopy, were not inconsistent with that style.

''It's not for a funeral. But it's not for a 5-year-old's birthday party either,'' Nevel said.

''It's not an imitation Mies. That would be stale copying,'' he said. ''But it's within the vocabulary of the original campus.''

Nevel's firm, Mekus/Johnson Inc., was hired last spring to ''clean up'' the front of the building.

He said he submitted plans for redoing the library's main entrance, including the canopy, and that the plans were approved.

But institute president Thomas Martin said the plans had not been given a thorough review. He said students, faculty and officials returning to campus felt the renovations were out of place.

Martin said he has asked George Schipporeit, the school's architecture dean, to come up with an acceptable design.

''Our overall plans still call for a canopy, definitely,'' he said. ''That helps with the winter salt and slop. We've just put $10 million in that building and we want to protect it.''