The white (hedj/shesep) crown suggests omnipotence and purity. The name of the holy city of Memphis meant "White Walls." White sandals were worn at holy ceremonies. The material most commonly used for ritual objects such as small ceremonial bowls and even the embalming table for the Apis Bulls in Memphis was white alabaster. White was also the heraldic color of Upper Egypt. The "Nefer" crown of Upper Egypt was white.
The pure white color used in Egyptian art was created from chalk and gypsum. The white crown appears like a linen turban and suggests purity. The red crown suggests the blood that purifies. The double crown association with Horus speaks of both purity and blood sacrifice. Among the ancient Afro-Asiatics these were linked as is evident from linguistic studies.