go to proofhouse .com and click colt serial numbers,this will tell you the age of your colt.
Impossible to answer without a detailed description of all markings, features, barrel length, sights, grips, box, papers, accessories, condition, type of action, etc..
Serial number shows it is a single action revolver made someime after 1978.
1927
1895
1962
depends on the model revolver. single action just in front of trigger guard............ modern revolver bottom of butt............
1970
1959
about 1907
about 1880
1897
1910