Liquid carbon is likely to appear silver-colored at the atomic level, resembling most metals, unless the pressure is too low, which would make it an insulator. The discussion highlights that liquid carbon may appear white due to heat or a bright gray when colorless. A referenced paper discusses the phase transitions of carbon between solid, liquid, and gas states. However, the paper does not provide a specific spectrum for liquid carbon. Overall, the consensus is that under typical conditions, liquid carbon exhibits metallic properties and a silver hue.