This crown, called Hedjed, is the crown of Upper Egypt. This conical shaped headpiece was worn as early as 3000BC. The White Crown could actually have been green because it is believed to be have been made from reeds.
The earliest image of the White Crown so far is in Northern Nubia (Ta-Seti) around the Naqada (pre-dynastic) period. So it could well be that the “White crown clan” migrated northward and their regalia was adopted by the Egyptians or it could be that the conquering Upper Egyptians took the White Crown as their own as they absorbed the kingdom into the new unified state, like they did for Lower Egypt.
The god Osiris is often shown wearing the White Crown of Upper Egypt and often became the Atef crown by being combined with feathers. After the unification of Upper and Lower Egypt it got combined with the Red Crown of Lower Egypt and was called the Pschent.
The symbol sometimes used for the Hedjet was the goddess, who is the Uraeus (cobra) shown next to the head of Nekhbet (the vulture goddess) on the Pschent.
The Red Crown.
The Red Crown, Deshret, is the crown of Lower Egypt and was as stated above got combined with the White Crown after the unification of Upper and Lower Egypt. No Red Crown survived so we can only guess what is was made of. Copper, reeds, cloth and leather have been suggested as material but this is in all honesty nothing more than a wild guess.
An early image of the Deshret can be found on the front side of the Narmer Palette; here we can see a victorious pharaoh wearing the Red Crown.
Since there has been no crown found in any tomb, even in relatively intact tombs, it could be possible that the crown was passed on from one pharaoh to the other.
The Double Crown.
This crown is also known as Pschent and symbolizes the unification of both Upper and Lower Egypt. The ancient Egyptians generally referred to the Double Crown as Sekhemti, which means the “Two Powerful Ones”. In general the invention of the Double Crown is thought to be done by Menes, a pharaoh of the first dynasty, but the first to wear the Double Crown can have been Djet, there is a rock inscription that shows his Horus wearing a double crown.
Surprisingly there are far less representations of the Double Crown then there are of the White and the Red Crown alone. Sculptures of the Double Crown not very often show the curled wire that often can be seen in representations of the Red Crown, sometimes because it is broken off but most of the times it just isn’t added.