The Empire State Building Lit Up in Eagles Green. Giants Fans Weren’t Thrilled.

In a nauseating hometown sight for Giants fans, the lights atop the Empire State Building turned green and white on Sunday night — and it was definitely not in honor of the Jets.

Instead, it was for the Giants’ hated rivals, the Philadelphia Eagles, who won the N.F.C. championship on Sunday and advanced to the Super Bowl, just a week after knocking the Giants out of the playoffs in a humiliating blowout.

The light display really did not go over well.

The New York City Sanitation Department called it “treacherous, traitorous, and unforgivable.” Keith Powers, a City Council member who represents an area of Manhattan that includes the Empire State Building, deemed it “absolutely ridiculous.” The New York Post considered the news front-page-worthy, calling it an “off-color” mistake. The Daily News asked, “Where’s yer loyalty?!?”

“What on Earth… Let me close these blinds,” Julian Love, a player for the Giants, said on Twitter.

And there were thousands more responses from Giants fans, as well as from other N.F.L. rubberneckers, who were aghast at the betrayal.

To many, seeing Philadelphia’s triumph smashed into the faces of New Yorkers, on their own turf, violated a cardinal rule of sports fandom: If you can’t be happy about your own team, you can at least root for the misfortune of your rivals. An Eagles win is a Giants loss, even if they’re not playing.

Giants fans were in no mood to see reminders that Philadelphia sports fans would experience a rare moment of joy. Now, every Giants fan who works with that jabroni from Fishtown is going to have to listen to him go on and on for the next two weeks, and he’ll probably wear a Dawkins jersey to work, that monster. The less said about it, the better.

Though this wasn’t the Empire State Building’s most popular moment, it frequently changes the colors of its tower lights to reflect national and world events, and to recognize sporting triumphs. Just this month, the lights turned red, black and green for Martin Luther King’s Birthday; glowed red for Lunar New Year; and turned yellow to commemorate the victims of the Holocaust.

The lights even turned blue to honor the Giants on Jan. 13, when they clinched a spot in the N.F.L. playoffs after a season that exceeded expectations. In past years the building has honored Super Bowl champions, including in 2018 when a similar backlash formed after the Eagles won.

After about four hours of comments piling up on social media on Sunday, the building tweeted shortly after 10 p.m. that it was switching to red in honor of the Kansas City Chiefs, who had just won the A.F.C. championship. At long last, the nightmare was over.

“That hurt us more than it hurt you,” the building’s Twitter account said.