Crude oil is not always black as is
often depicted in movies. Petroleum is another name for crude oil,
which is unprocessed oil. The outputs of processing crude oil are
called petrochemicals. The color varies greatly from clear to black,
and and in viscosity, from water to almost solid, based on the
concentration of hydrocarbon molecules and other compounds in the
mixture. For instance, Pennsylvania grade crude oil is typically
greenish in color.