The Empire State Building is perhaps New York City's most recognizable skyscraper. Now, it may face some competition – a proposed 67-story building would be built just a few blocks away.

Whatever the outcome of the contested proposal, the Empire State Building will remain unique in its long history, and also in its symbolic lighting displays. The peak of the building has been illuminated in practically every color and combination of colors imaginable since colors were introduced for the building in 1976.

The first light to grace the top of the Empire State Building was a white searchlight beacon, which was turned on in November of 1932 to celebrate Franklin D. Roosevelt winning the presidential election. This was upgraded to four revolving beacons, called the "Freedom Lights," in 1956.

Colorful displays

The Empire State Building's lights went colorful in 1976, when the tower was lit in red, white and blue in celebration of the American Bicentennial. The lights were then tinted green and red in December for the holiday season, then yellow and white in the springtime.

Since then, the variety of colors has continued to grow, and by the mid-1980s, the lights glowed with colors on a regular basis, symbolizing holidays and special events. [Image: The Building lit in commemoration of the 60th anniversary of the founding of the People's Republic of China.]

In August of 2006, the Empire State Building's official Lighting Partner program was established in order to screen and approve the requests that the building receives regarding the colors that should be lit on particular days. When there is a lull between multihued displays, the light simply shines a stark white.

Over the years, the lights have been used to salute everything from fictional characters to corporations.

In 1995, the building's tip shone azure to mark the rollout of blue M&Ms. In 2008, to celebrate the release of a new Mariah Carey album, the lights shone purple, pink and white down on the city – Carey's favorite colors. They glowed neon green on April 23, 2009, in honor of the 25th anniversary of the first Teenage Mutant Ninja Turtles comic book.

Other cartoon characters that have influenced the Empire State Building's luminescence include The Simpsons and Popeye. The lights were yellow the day that "The Simpsons Movie" was released,  and a green-hued display represented the vivacious sailor's love of spinach on his 75th anniversary.

The building also shines in the colors of New York sports teams when they have home games.

While the color scheme usually sticks to a limit of three colors, it does on occasion make exceptions. In 2009, a psychedelic, tie-dye rainbow of colors was used to honor the Grateful Dead exhibit at the New York Historical Society.

The lights have been used to bring attention to good causes as well. The building has been lit with pink and white for breast cancer awareness on special days since 1990, and in other colors for National Osteoporosis Society and Alzheimer's disease awareness. The Empire State Building even went “green” in 2008 by turning off the lights in honor of Earth Hour.

During certain times of the year, the building dims its light so as not to distract migratory birds. The lights are usually turned off at midnight every night.

No stranger to controversy

But the Empire State Building's lighting program has seen its share of controversies over the years. The building's managers repeatedly rejected petitions over the course of six years to light the building purple in honor of Gay Pride. This changed in 1990, and the tower is now lit up lavender and white on the night of the city's Gay Pride Parade.

Currently, the Empire State Building's official Lighting Partner program is under fire for rejecting to honor Mother Teresa on what would have been her 100th birthday. The Catholic League, a religious advocacy group, applied to have the building shine white and blue on Aug. 26, 2010, but its request was denied by the building's owner, Anthony E. Malkin.

"As a privately owned building, Empire State Building has a specific policy against any other lighting for religious figures or requests by religions and religious organizations," Malkin said in a statement.

Critics say this policy seems to contradict the building's past approved lighting choices, which included white and gold lights in honor of Pope John Paul II's visit to New York in 1995, as well as the dimming of the lights to mark his death in 2005. The building also posthumously honored Cardinal John O'Connor in 2000, displaying the red and white colors of his position.

This article was provided by Life's Little Mysteries, a sister site to LiveScience.