I am an American currently living in Hong Kong and France (married to a French woman with one son and one daughter) and have long wished to trace our history in Ireland. I will ask my father more, but the story passed down to me suggests that 6-8 Colmey brothers left Ireland around 1870. They fanned out to New York, MA, and the Midwest and at least one, or possibly his son, became one of the America's leading lawyers and later a judge. My great,great grandfather, one of the brothers moved to Chicago and worked for the railroad there. Once, during a trip to Ireland I saw Vincent Colmey in the phone book and tried to call but he was out at the time, and time moved on.
Also, there apparently is a town or village called Colmey in Belgium -- I'm going to check it out now. Let's stay in touch, and we can tell you about the Colmeys in the U.S.