Supposedly royal purple comes from the color of the insides of a sea snail, and this, erm, sea snail "juice" was used to dye royal cloaks and such waaay back in the day. The snails are tiny so it took loads of them for one garment.
If you were to change the color associated with royalty, what color would it be and why?
Hmm...It would honestly be a combination of Black, White, and Gold as..well royalty is supposed to stand out, right? Those colors would make one stand out.
If you were to change the color associated with royalty, what color would it be and why?