Both the Colossus and the Sathanas have an equal amount of hitpoints (1000000), the Sathanas has 4 BFReds with 1900 damage (I think) and 8000 range, the Colossus's default BGreen causes about 1100 damage and has a range of 4000m. The LRBGreen is the overloaded version of the BGreen, with higher damage and a range of 8000m. The Sathanas's beams recharge in less than 10 secs (like most Shivan beams), while the LRBGreen recharges in 30 secs. Now that's why the colossus needs 10 minutes or so to destroy the Sathanas while the Sathanas blasts the Colossus in less than a minute.
Anyway, try putting a Lucifer from FS2 and a Colossus in front of each other and beam-free only a few TerSlashers and the Lucifers beams. The Lucifer nearly destroys the Colossus, because the Colossus can only attack with its small front cannons while the Lucifer atacks with its quick main guns many times, which recharge in 10 secs. However, if you give the Colossus an attack order and beam-free all the beams, it will pulverize the Lucifer with its BGreens. It's the same with the Ravana.
To make a Terran Sathanas out of the Colossus, replace its BGReens with BFReds and its TerSlashers with LReds.
Oh, and the tech description for the Lucifer from FS1 says it has 3 beams because the original design had three arms, like the Cain/Lilith (look at the credits of FS1). Then they changed that to two and later, they added 2 more to the sides (those seen in the Tombaugh station attack and in the FS2 intro), but those did not appear on the ingame version.