[citation needed] The original Trooper was a heavy-barreled version of the Officers Model Match and was based on Colt's medium I[1]frame.

Early blued Troopers boasted a two-tone color scheme with dull Colt Royal Blue on the flat surfaces and a black bead blasted texture on the edges and cylinder flutes.

The Trooper was targeted at the entry-level and Law enforcement service-level segment of the firearms market while the highly polished and expensive 357 model revolver was intended to be their premium offering.

[2] In the late 1960s, Colt began to be concerned with a decline in its market share because of price increases brought about by the high labor costs inherent in its manufacturing processes.

Intended to be the first major advancement of Colt's designs since the beginning of the 20th century, the MK IIIs used a new ‘J’ frame and had no parts interchangeability with older models.

[4] The .357 Magnum Trooper was the premier offering of the new product line, featuring a heavy barrel with a solid top rib as well as a shroud which protected the ejection rod.

[4] The Lawman was a .357 Magnum 'service grade' or 'police issue' version of the Trooper, and somewhat of an economy model intended for law enforcement looking for cheaper sidearms or private armed security.

[3][4] 1982 - 1985 As with the MK III, the Mark V series was an entirely new product line of models which included Official Police, Lawman, and Trooper variants.

Internally, Colt did away with the sintered iron MK III lockwork in favor of cast parts, and improved the trigger action with new components and a shorter hammer fall.