Behind-the-scenes look at how buildings create light-up messages stories high

CHICAGO -- It's no secret Chicago has one of the best skylines in the world! But the Blue Cross & Blue Shield building on E. Randolph street grabs the attention of millions with their positive messages.

Did you ever wonder how a building creates illuminated billboards? Here's a behind-the-scenes look at how electricians manually create these messages!

"Usually around 5 o'clock, the day a message has to go up, we begin pulling shades," says head electrician Roy Swanson.

The messages displayed include everything from health and wellness to Chicago sports teams.

Vice President of Government and Community Relations, Harmony Harrington, describes the messages: "Some memorable lightings have been 'Live the Dream' in commemorance of Martin Luther King Day, messages to support our front line workers, rainbow colors and the word 'Pride." We lit our building in support of Chicago sports teams like the White Sox, the Cubs, the Bulls... we've even lit it with the Stanley Cup for the Chicago Blackhawks."

Swanson explains the typical length of a word is 6 windows wide. Each letter is 5 stories high. After he creates the message on his computer, he then has to build it backwards!

The electricians that closed the blinds are looking at the windows from the inside out, so Swanson taught himself out to write backwards!

Swanson says, "You don't want to spell anything wrong!"

But not every message makes it onto the building.

"We don't put everything up on the building front. We don't do proposals or wedding announcements. But we do try and partner with local organizations to bring awareness to key health issues," Harrington said.

Even though the messages are always white, Swanson explains there are colors that illuminate the building.

"We have beams on the outside of the building, they're stainless steel columns. And we have LED lighting at the base of all of the columns. And we change the colors at the beams. The letters will always come out white because we have white light inside the building, and that's what you're seeing through the shades. So the color actually comes from the columns."

Everyone from the building managers to the electricians to the Chicagoans who live in the city take pride in the building messages.

"It's cool to know that you're the one that was part of that message going up. And it's usually because something good has happened," Swanson said.