The "Choshen", or breastplate was first worn by the High Priest Aharon HaKohen, and subsequently by every High Priest in the First and Second Temples.
Each of its 12 stones denoted a different tribe of the 12 Tribes, and was a different color.
Colorful gold filled
"Choshen" 12 Tribes Breastplate design
What is Gold Filled?