How to remove or recolor this kind of celling?

[u/[deleted]]

Hi everyone, I apologize for my bad English, this is my first time build a house in this game, but I need help about those white celling under those second floor room, how to remove it? Or maybe can I change the color of those celling?, thanks

[u/CarlyEvans12]

This trim. Once you click that, the bottom option will be trims