Oranges are a mid-tier Color. They are the mechanics of Society and provide systems support upon starships and all manners of mechanical enterprises. Darrow theorised that some might even be able to be pilots.
The only named Oranges in the Red Rising Trilogy are Cyther, who appears first in Golden Son and is briefly mentioned in Morning Star, and Harnassus, who is mentioned in Iron Gold and appears in Dark Age.
Orange doesn't have class honorifics like higher colours.
Many Oranges are depicted like low-colors, despite being mid-color. Both in Golden Sun and Morning Star, oranges are said to live in the slums of Hyperion and Tinos, alongside Reds, Pinks, and Browns.
Pierce confirmed in a tweet that Oranges called "Artificers" make the famous Gold weapon, the razor.