Helping with adding materials to 3d model

Hey everyone,

So I bought and imported a 3D model into my project as an .fbx file. It looks like it has 3 main components and most of the colors are correct, but I'd like it to have white stripes.

This is how my file currently looks. And I'd like the hat to look more like this: 

Is there something I'm missing? I was able to do this in Spark AR pretty easily because the "Hat" part of the model had 3 different materials whose colors I could set. In Lens Studio, I only seem to be able to set the base color as red and not access any other colors.