How to give two different colors/materials to the same mesh

Hello everyone! I’m new to this forum…
I have an object that has different meshes inside.

Is it possible to assign two different colors or materials to a mesh?
I mean I would get the visual effect like a bottle of glass, with some water inside.
Thanks

Hello!

mesh1.material.color=new THREE.Color(0x3B93C1);
mesh2.material.color=new THREE.Color(0xFF3FD6);

that’s easily possible if the meshes carry separate materials, if they don’t you open up blender and create a section from the inner meshes.

demo: https://69511.csb.app

sandbox: Aesop bottles (forked) - CodeSandbox