I agree this would look good. However the game's visual simplicity boosts its ability to be quickly learned, which is critical for such a new kind of game. To not ruin this, you might consider a paradigm such as {<40% brightness, >60% gray, glossy finish, smooth texture} = non-interactable and {>60% brightness, <40% gray, matte finish, bumpy texture} = interactable.

I really like how at the moment, when you are looking where to go, the bright color of the grab-able objects creates a eye-catching visual path to follow.

As a side note the zipline's cord is currently the only dark-gray colored object that the player can interact with. Maybe consider increasing its texture's brightness?