NEW YORK — The Mets are lighting up Citi Field, even before their batters step up to the plate.

About 70 front-office staffers scattered around the ballpark for over five hours earlier this month to install 3,500 strips of LED lights on each railing ahead of the Mets’ first home postseason game.

When the games reach the late innings and the sky darkens, the Mets dim the stadium lights as the ribbon boards flicker in blue, and then they activate the rail lights that glimmer in the team’s colors of royal blue and orange, and later red, white and blue for “God Bless America.”

“It’s a cool fan experience,” Mets outfielder Harrison Bader said. “Obviously, this is entertainment, so I’m sure the fans enjoy it.”

In-game light effects have been on the increase for a decade. The Yankees started blinking the lights atop their stadium to excite crowds during home run trots in 2016. Even historic venues like Fenway Park and Wrigley Field have been upgraded for startling light shows.

After the 2023 season, Musco Sports Lighting replaced the halogen lamps installed for Citi Field’s 2009 opening with LEDs. That enabled the Mets to implement dramatic entrances for closer Edwin Díaz. Fans started posting clips.

“I looked at TikTok,” said Trisha Donlin, the Mets’ vice president of brand marketing. “All the videos were of our light sequences, whether that be our pitching change, our Diaz entrance, home runs. These are all moments where we trigger the greatest lighting effects. And so I was like, OK, this is what everyone’s talking about. This is where we need to double down.”

When the Mets beat the Brewers to win their NL wild-card series and ensured postseason home games, the team contacted PixMob, a Montreal-based company founded in 2006 that distributed ski caps with LEDs to fans for Bruno Mars’ halftime show at the 2014 Super Bowl in New Jersey’s MetLife Stadium. PixMob has since worked with NFL, NBA and NHL teams and musicians including Coldplay, Bad Bunny and George Strait, often supplying light-up wristbands for the audience.

PixMob did a Citi Field walk-through on Oct. 4. Technicians installed 32 transmitters for the infrared signals on the upper deck, and Mets employees fastened the Nova Mini LED strips with zip ties on Oct. 7, a day before the team hosted the Phillies in Game 3 of the NL Division Series.

“We can do effects, like a chase around the stadium or up and down,” PixMob account manager Phil Belanger-Bishinga said. “We program in Montreal in our warehouse and then our light operator on site can trigger those effects.”

Brendan McKeon, the Mets’ executive director of in-game operations, operates the ribbon boards and LEDs, as Jon Barron, the manager of in-game operations, prompts the PixMob team on site to coordinate timing and colors.

The Mets hosted the Dodgers in Game 4 of the NL Championship Series, and the Guardians hosted the Yankees in Game 3 of the ALCS on Thursday but the games ended too late for this edition.