Unless you provide the model, your question is almost impossible to answer. If you don't want to, go to Proofhouse.com and research the Colt serial numbers.
A Colt police positive special .38 with sn 262352 was produced around 1922.
A Colt Python serial number 35128e was manufactured about 1964
The government issued Colt with that serial number was manufactured by Colt in 1942.
Colt 1911 .45 serial # 171885 was manufactured in 1917.
1943 by colt
You will have to call Colt and tell them the serial number.
The Colt with that serial number was made in 1976.
It was manufactured in 1944.
If that is the colt combat commander, it was manufactured in 1962.
made by colt in 1943
It was made in 1945 by Colt.
A Colt with that serial number was made in in 1956.