Colin, or The Anointed One, was sired when his bus was attacked by The Master's vampires. He was made because it was written that The Anointed One would lead the Slayer into Hell, and be The Master's most powerful weapon.
For a few months time, Colin learned The Master's teachings on how he thought vampires should function as a society. The Master treated him very well.
The Anointed One fufilled his destiny by leading Buffy to The Master's lair. True to the prophecy, Buffy was killed. What The Master didn't count on was her being revived, and killing him.
A few months later, The Anointed One gathered some remaining vampires from The Order to perform a ritual which would bring The Master back to life. His plans were stopped indefinitly when The Slayer killed most of the remaining order and by bashed The Master's bones into dust.
The Anointed One's hated of The Slayer lead him to continue to try and kill her. At this time, Spike came to Sunnydale, and said he would kill her. He tried and failed, and The Anointed One was very angry. Spike had enough of taking orders from a kid though, and lashing out, and threw The Anointed One into the sunlight, killing him instantly.
At the time of his death, The Anointed One had spent less then a year as a vampire. When he was killed, his body burned very fast because of his youth. He is never seen in his vampire form, and never shows any typical vampire traits except for his disire to do evil. This is probably because he never needed to, as he is only a child, he would do no good in battle anyway. The Anointed One was the only child vampire ever seen on the shows up until Holtz's daughter was shown in an episode of Angel. A vampire wouldn't normally sire a child since they would be pretty useless, in Holtz's daughter's case, it was to make Holtz feel terrible, and in The Anointed's case, it was to fufill a prophecy.