You guys remember that episode in Season 3, where Jay and Cole are in the trash compactor, and Nya has to cut either the blue or black wire? Well, the episode cuts away before she cuts the wire, and later, she says that she'll never tell. As far as I know, there was never an official answer. In fact, in this video https://www.youtube.com/watch?v=Wu1brZr1Myg&list=WL&index=27&t=0s , when the voice actress was queried, she says the color, but a buzzer sound effect censors it. And I'm no good at reading lips.
Anyone know if there was ever an official answer? Or did the writers purposefully leave it ambiguous so we could all spectulate?