godot/editor/icons/BoxShape3D.svg

<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><path fill="#2998ff" d="m8 1-7 3v8l7 3 7-3v-8z"/><path fill="#5fb2ff" d="m8 15-7-3v-8l7 3z"/><path fill="#a2d2ff" d="m1 4 7 3 7-3-7-3z"/></svg>