Before insulating the ch.water piping ,(in high rise building) it is painted red oxide paint. Is it advised to paint this red oxide painted piping to paint black before insulating?

Is it advised to paint this red oxide painted piping to paint black before insulating?
What reason would there be in painting a pipe black before insulating it? Just curious, Tom

The pipe will need a condensation preventive coating before insulating unless the insulation is impervious to condensation. Wet insulation is like no insulation at all.

What is the painting supposed to be fore? What does it accomplish

Red oxide is a rust prevention coating or paint grip paint as we called it.