Toga pulla is black and weared while mourning, toga picta is purple and weared by victorious generals,emperors and counselors, toga praetexta is weared by children and judges. There is red sculpture in Levant region since Roman period. In Levant region, Petra is called rose-deep red city.This is because the temples, graves are located in deep red rocks. Purple means looking for the invisible since it is at the end of the electromagnetic a result it is the crown chakra colour. Crown chakra is fed by the sun. Porphyr symbolises power and authority but red symbolises after life since prehistoric times, just like ochcre. Ochre is hematite like Porphyr and used for protecting the buried body bones.
Former name of Egypt is Kemet. In hieroglyphs, KEM (the letter I6) means the black Nile Delta mud.Osiris, Ptah and Anubis symbolises death and their skin are black. Black as in mourning is older than Romans. It goes to prehistoric times...
Black means hopelessness since prehistoric times. Black means reborn because beginning was dark also womb is dark as well.