Fix nullable support for custom modeldoc nodes random_color model node acts as a fallback not override Update default balloon models to use random_color as default color Rather than tinting the base material, we use random_color modeldoc node to set the default color of the balloon. This makes the balloon properly colorable in gamemodes rather than overlaying one color on another for colored balloons. Also added break particles to balloons. Merge branch 'master' of sbox