The bunker and the colors
Branch warns that Poppy's party will draw the Bergens, and nobody listens. When the Chef attacks, the Trolls hide in his bunker. He tags along on the rescue, grumbling. Bit by bit we learn he lost his colors as a child: his singing led the Chef to his home and his grandmother, Rosiepuff, was captured. He swore never to sing again. At the lowest moment he sings "True Colors," and the colors return.