Callum, a charming Scottish boys' name just beginning to be heard in this country but high on the list in England, Scotland and Northern Ireland, is worth consideration as a less popular alternative to Colin and Caleb, etc.
Kyle MacLachlan chose Callum for his son. Callum might also be spelled Calum; in Ireland, the name became Colm, and in Scotland it's sometimes used as a pet form of Malcolm.
Callum was popular among early Christians because the dove was a symbol of purity, peace and the Holy Spirit. St. Columba was one of the most influential of the early Celtic saints.