Gelatin appears to be a lime flavored gelatin. His main body is jade and his bottom lighting is spring green.
In BFDIA, Gelatin has a very laid back personality as he is calmer than most contestants at handling situations. He is presumed to have made the freeze juice and the anti-poison, which probably means that he has a resourceful amount of knowledge on chemistry. He also cares about people around him. He saves Match from getting squashed by the HPRC in Zeeky Boogy Doog. But not always. He threw his own teammates out from Puffball just because there wasn't enough room in The Long-lost Yoyle City and Get Digging. He might be claustrophobic, meaning that he is afraid of small spaces.
In BFB, he retains his laid back personality, but he's more reckless and inconsiderate than he was in BFDIA, supported by the fact that he kept throwing forks at Death P.A.C.T. (but he stopped doing that since "Today's Very Special Episode") and suggesting to kill Bomby to their advantage.
He's also a bit more immature, especially towards Donut.