Jefferies class

The Jefferies class was a Federation starship type, a tier 2 cruiser class in Starfleet service in the early 25th century. 

History and specifications
After the heavy cruiser USS Enterprise (NCC-1701) returned from its historic five-year mission in 2270, one idea of an extensive refit included the Phase II concept, with a projected launch in 2271. The design was notable for the prominent registry number painted on either side of the secondary hull, and the use of square warp nacelles on an Enterprise. 

The Enterprise was instead refitted to configuration, and launched after 2.5 years of work in 2273. 

Late in 2410, Starfleet revisited several "iconic" starship classes with upgrades to match them with the newest starship designs. These were called legendary starships. 

Following the Battle of Excalbia in early 2411, which saw the prominent involvement of hero ships from the Federation's past and present, the newly-minted Jefferies-class was added to the lineup of tier 2 cruisers. 

Alternate timelines
In the  continuity, the Jefferies-class Enterprise was relaunched in 2271 and visited Earth. 

This Enterprise was equipped with small, aerodynamic shuttlecraft, including the. 

The USS Enterprise (NCC-1701) commenced a second five-year mission under Captain James T. Kirk. Soon after, a Romulan scout ship crashed into the saucer section. The situation was defused by Captain Kirk and science officer Xon, though the Romulan crew committed suicide. 

Livery
In the 25th century, the hull design of the Jefferies-class legendary cruiser allowed its commanding officer to choose from different livery s. These could be modified at shipyards. The material options included numbered Types, Upgrade and Veteran. 

Furthermore, the installation of deflector shields from specific factions modified the hull appearance, including shields from the Reman Resistance, the Breen Confederacy and the Dominion.