Colin McConnon, universally known as "Col", was a human the Doctor and Martha Jones met on the planet Sunday in 2108.
He was one of the First Wave of 800 settlers to the planet. Consequently, he had to endure a cataclysmic tidal wave which killed off half the original colonists and laid waste to Sunday City, the main settlement. He then became involved in the reconstruction efforts that were necessary to pave the way for the Second Wave.
He was Professor Ty Benson's chief assistant in her zenozoological study of Sunday. Like her, Col had a pseduo-parental relationship with Candy Kane. He regarded Chief Councillor Pallister with disdain, thinking him a mere political opportunist.