At least two, probably three, alien races have been called "The Orange".
1. The Orange would be a reptilian or a hybrid reptilian species. Some think they may be a hybrid sub-species of the greys. One whistleblower, though, claims to have seen documents that state that the Orange are the ones that created the smaller Greys.
The Branton material: "They are said to be "based below the west slope of Mt. Archuleta near 'the Diamond'. Some suggest that the 'Orange' are a so-called 'hybrid' race with PARTIAL reptilian-like features yet possessing human-like reproductive organs and even certain artificial or cybernetic features. It is possible that the 'Orange' consist of hu-brids and re-brids in that some or most of them may possess a human soul- matrix and therefore may be 'human', although information on the 'Orange' is presently sketchy. They have also been described as being involved in the scenarios taking place in the tunnels below the Nevada Military Complex aswell. William Cooper briefly mentioned the 'Orange' based on memories of top secret documents he had read while in Navy Intelligence: (...)"
Note that other sources, too, confirm the existence of bases with Orange residents.
The Branton material adds that "The 'Orange' -- which sources seem to indicate 'may' actually be a double term used to describe two different types of entities, a reptilian hominoid group with scaly orange skin and a more human-like group with 'red' hair -- may have established themselves in Orion or Barnard's Star."
Other sources, too, locate this reptilian "Orange" race in the Orion system (and confirm that they are related to the Greys). One source, however ("Matthew") says these reptilian hybrid "orange" are from Sirius. (?)
Also note that the alien pictured on Whitley Strieber's Communion looks like an "Orange."
2. As indicated in The Branton material, the "Orange" is also used for a race of "red haired humans" that would come from Barnard's star. It's not clear whether this would be a separate race, or whether these are the same as the Lyran Redheads, mentioned below.
Lyssa Royal: "Their hair was red to strawberry blonde in color. The skin tone very, very fair; these entities had a difficulty exposing their skin to certain frequencies of natural light, due to the planet they sprang from. Some of these were also giant in stature, though there were some who were average human size. Eye color was generally light to what you would now consider green, though it is a different quality of green than you see upon your world. These entities were some of the first Lyran pioneers. (Pioneers is a very kind word, for there are many worlds that consider the red-haired ones to be the invaders, marauders and the basic havoc-wreakers of the Lyran genotype)."