'Blue' in the Bible

clothed with blue, governors and rulers, all of them attractive young men, horsemen riding upon horses.

Byssus with broidered work from Egypt was thy sail, to serve thee for a banner; blue and purple from the isles of Elishah was thine awning.

these traded with thee in sumptuous clothes, in wrappings of blue and broidered work, and in chests full of variegated stuffs, bound with cords and made of cedar-wood, amongst thy merchandise.