Exodus 28:31

28:31 “You are to make the robe of the ephod completely blue.

Exodus 39:22

The Other Garments

39:22 He made the robe of the ephod completely blue, the work of a weaver.

Exodus 29:5

29:5 and take the garments and clothe Aaron with the tunic, the robe of the ephod, the ephod, and the breastpiece; you are to fasten the ephod on him by using the skillfully woven waistband.