The producers of Gotham have teased the arrival of the show’s version of Harley Quinn by the season’s end, so it’s hard not to imagine this nod is intentional.
While the costume doesn’t look like Harley’s, she has a variety of looks in the comics based off of two central colors.
This look was used in Suicide Squad, making it the more recognizable look for Harley.
The closest is Jerome, but even he hasn’t been confirmed to be the Clown Prince of Crime in any concrete way.