Even after it was found that one of the most effective purple dyes used in ancient history was taken from a gland in a ...

The scarlet, purple, and sapphire hues that adorned curtains and robes at the Holy Temple in Jerusalem likely came from sea snails processed at a 3,000-year-old dye factory in modern-day Haifa ...

If a sign tells you to follow the purple skull ... calls the color-completion effect. The phenomenon causes an image to skew toward the color of the objects that surround it.