Verses with the word colts in the Old Testament (3 verses):

Genesis 32:15
Thirty milch camels with their colts, forty kine, and ten bulls, twenty she asses, and ten foals.

Judges 10:4
And he had thirty sons that rode on thirty ass colts, and they had thirty cities, which are called Havothjair unto this day, which are in the land of Gilead.

Judges 12:14
And he had forty sons and thirty nephews, that rode on threescore and ten ass colts: and he judged Israel eight years.