If it has one, it will be the last three digits of the serial number.
your colt SAA if it has a serial number of 502479SA was made in 1969.
Call Colt and they will tell you.
Your Colt SSA was made in 1907.
Your colt was made in 1956.
Proofhouse.com has Colt sn data.
about 1891
by the serial number
Proofhouse.com has Colt sn data.
about 1928
It was made in 1962.
1919
1978-1980.