NEWARK — They waited patiently, several thousand of them, outside the Prudential Center here on Friday night. They were mostly young, a combination of futuristic cool and slightly awkward. The more extravagantly attired were beyond mere extravagance: shiny clothes in bold contrasting prints, hair dyed in colors known to no rainbow.

They were K-pop fans, here for the first American performance of 2NE1, the K-pop — that’s Korean pop — stars. And they were being made to wait, unhappily, for unspecified reasons well past the time that doors were supposed to open, then also past the time that 2NE1 (pronounced “twenty-one” or “to anyone”) had been meant to take the stage. There was at least one report of fangirl tears on the street before the arena’s doors finally relented, and the crowd clogging the sidewalks was slowly herded to seats, just dodging the rain that would have compromised those outfits.

The members of 2NE1 awaited them, taking the stage in track jackets with their names — CL, Dara, Minzy, Bom — spray-painted on the back and, for some of the band, their own faces airbrushed onto the front. (The clothes for the tour were by the fantasist designer Jeremy Scott.)

“I’m going to make this show worth the wait,” CL assured the crowd, just as the group began “Clap Your Hands,” which sounded like a carbon copy of mid-2000s up-tempo R&B, and during which the group’s backup dancers were making a scene that could have been from “Breakin’ 2: Electric Boogaloo.”