Exodus 28:31
The robe which goes with the ephod is to be made all of blue;
Exodus 28:4
This is what they are to make: a priest's bag, an ephod, and a robe, and a coat of coloured needlework, a head-dress, and a linen band; they are to make holy robes for Aaron your brother and for his sons, so that they may do the work of priests for me.
Exodus 28:28
So that the rings on the bag may be fixed to the rings of the ephod by a blue cord and on to the band of the ephod, so that the bag may not come loose from the ephod.
Exodus 39:22-26
The robe which went with the ephod was made all of blue;
Leviticus 8:7
He put the coat on him, making it tight with its band, and then the robe, and over it the ephod, with its band of needlework to keep it in place.