Chicago’s cold white winter will get a purple tint Sunday in honor of Northwestern’s official sesquicentennial.

A parade of purple lights will illuminate Michigan Avenue and Evanston on Sunday, which marks the 150th anniversary of the date Illinois Gov. A.C. French signed the university’s charter.

Several downtown Chicago buildings will be lit in purple, including the new Goodman Theater, Sears Tower, Aon Center and Bloomingdale’s on Michigan Avenue. Bridge floodlights over the Chicago River also will cast a purple hue.

Al Cubbage, vice president for university relations, said NU received “good cooperation” from the buildings downtown.

“Obviously we are very pleased that there will be a light display next week,” he said. “I think a lot of people downtown will wonder why all of these buildings are shining purple lights, but the color is associated with Northwestern pretty strongly.”

In Chicago’s most prominent display of NU spirit, the Smurfit-Stone Container building will spell out “NU 150” in purple light bulbs on top of its slanted diamond-shaped roof. The building, at 150 N. Michigan Ave., can been seen from as far south as the Field Museum.

Nicole Spencer, the property’s assistant general manager, said engineers will arrange a grid inside the building that beams out the lighted message.

In the past, the roof has displayed the messages, “MS Walk,” “Cubs” and “White Sox.”

“We try to be supportive of community spirit,” said Spencer, who graduated from NU’s Law School in 1995. “Northwestern let us know that other skyline buildings were participating, and we wanted to be a part of it.”

Spencer said the “NU 150” sign, which will remain lit until Feb. 3, will cost the property owners a nominal charge for the labor. NU will not have to pay for renting the display, she said.

Monica Metzler, NU’s sesquicentennial director, said she hopes the lights will be fun for the city.

“It’s a great way for the city to share in the celebration,” she said.

But Chicago is not the only place where students can demonstrate their purple pride this week. The floodlights on Deering Library and the clock tower at Rebecca Crown Center will radiate purple beginning Sunday.

In addition to the light displays, NU’s anniversary will be celebrated in other ways.

On Tuesday, the Evanston Historical Society unveiled an exhibit that runs through June 8 called “Evanston and Northwestern: Athens on the Lake.” And any student wearing purple Jan. 31 will receive a free burrito from Chipotle on Church Street.

Also, Chicago Mayor Richard Daley, Illinois Gov. George Ryan and Evanston Mayor Lorraine Morton issued resolutions of congratulations to NU this week.

Some students said they were proud that NU’s birthday would be the talk of the town this weekend.

“It’s nice that both cities are showing support for our university,” said Hannah Peters, a Weinberg sophomore.