The makeup guys who worked on "Star Trek IV: The Voyage Home" called these orange-skinned aliens Efrosians, after Mel Efros, the Unit Production Manager of Paramount Pictures' movie.
The USS Saratoga's Efrosian, assuming he is typical of his race, had an orange complexion, long white hair, a Fu Man Chu-style moustache, and white irises (an effect produced by making the actor, Nick Ramos, wear white contact lenses). There was also at least one young, short haired, white-eyed Efrosian usher, wearing a United Federation of Planets badge on his uniform in the Earth-based. Although he's not visible onscreen, a FASA roleplaying manual of the time showed him to have white makeup (or tattoo?) streaks on his cheeks.
Now, of course, since most of this information didn't get conveyed that way onscreen, it is not what is known as "canonical". The novels, comics and new "Star Trek" series and movies are free to ignore the term "Efrosian", and some do. Novelizations are not canon. Vonda N McIntyre, the author of the ST IV novelization, was not aware of the new alien species term coined by the production because she hadn't seen the captions on the official stills. Being a term coined by the production, it perhaps carries as much canonical weight as the numerous alien species names coined by the costumer and makeup artist of ST: TMP.
The FASA role-playing people did see the caption, though, which is why they used the term in the licensed "ST IV Sourcebook Update", which is of equal canonical weight as the tie-in novelizations.
But a good alien design is worth revisiting. For the United Federation of Planets' President in "ST VI: The Undiscovered Country", the actor Kurtwood Smith (of "That 70s Show" fame) was given the familiar white mane and orange skin colouring of the ST IV Efrosian, plus solid blue-irised contacts. Since his pince-nez glasses have very dark lenses, as featured in one scene, we may assume that Efrosians see different light frequencies than most humanoids. Indeed, the text commentary on the ST VI DVD explains that the UFP President was originally intended to be blind.
Perhaps Efrosians are blind under our "normal" conditions, but can see better than us in ultraviolet or infrared situations. That would also explain the Saratoga's dark lighting on the bridge (in ST IV). Maybe the lighting wasn't just due to the invading Probe; it was already shifted to the red end of the spectrum to assist their helmsman to see?
Not everyone calls them Efrosians, though. In Decipher's "Aliens" sourcebook, that supports their "Star Trek" roleplaying game, the ST VI UFP President's photograph represents the Atreonids of Atreos IV. Before that, JM Dillard, in her novelization of ST VI, assumes that Federation President Ra-ghoratrei was a Deltan, no doubt due to a previous reference (in the ST IV novelization): that Deltan males actually had hair, so she simply followed the Vonda N McIntyre naming conventions for Deltans!
The more recent Efrosian names in ST novels, such as Ra Mhvlovi ("In the Name of Honor"), Hu'Ghovlatrei ("SCE: Home Fires") and Ra-Yalix ("Articles of the Federation") do sound similar to the exotic full Deltan names of Jedda Adzhin-Dall and Zinaida Chitirih-Ra-Payjh (in McInytre's novelization of "ST II: The Wrath of Khan").
The ST II Indian-sounding names were probably a salute to planet Delta IV's Ilia (and Bombay actress, the late Persis Khambatta) of "Star Trek: The Motion Picture". From what we saw of Deltans in TMP (and some extras dressed in TMP Deltan robes and headdresses in ST IV), and from what we were told in the media releases of the day, all Deltans are hairless, except for eyebrows and eyelashes. For those who've not read the ST II novelization, Zinaida was an original-to-the-novelization bald female partner of Genesis Project scientist, Jedda. The ST II script actually refers to Jedda being a Deltan - even though actor John Vargas wasn't required to shave his head. (We know that director Nicholas Meyer was trying to avoid all comparisons to TMP; by the time of "The Next Generation", the empathic Deltans had morphed into Betazoids.)
Above: Deltans, Ilia (ST:TMP) and Jedda (ST II), and the Betazoid, Deanna Troi (ST:TNG).
Their other two "partners" of Jedda and Zinaida are introduced and named in McIntyre's ST IV as: female Verai Dva-Payjh and male Kirim Dreii-Dall, who is described as having fine, rose-coloured hair down to his knees. Ah! The male Deltan with hair I mentioned earlier!
Note that McIntyre does add a Deltan science officer to the bridge of USS Saratoga, Chitirih-Ra-Dreii, in her ST IV novelization. While not in the same console position as the canonical/onscreen, white-haired, white-eyed Efrosian helmsman, McIntyre would have been working from the script only, and a few random stills of characters. I guess JM Dillard, when researching for ST VI, assumed that this guy, in the ST IV novelization, was meant to be the same race of alien. Thus, for a string of novels featuring cameos by President Ra-ghoratrei, he became a male, hairy Deltan - bumpy forehead notwithstanding. And I guess one can use it as an attempt to rationalize Jedda having a mop of onscreen hair for the ST II movie.
The recent novel "Titan: Taking Wing", the first of a new novel series, reaches a great compromise. Its Efrosian engineer, Doctor Xin Ra-Havreii, is said to be from... Efros Delta!
There was a Memory Alpha history/discussion recently where someone actually rang Mel Efros, former ST IV Unit Production Manager, to confirm the story about the race being named after him. At first Mel denied it, because he really had no idea. Then he mentioned the phone call to his son, who made Mel ring the guy back a few days later. They confirmed that yes, official Paramount publicity photos of the alien Saratoga helmsman had been captioned "Efrosian" by Kirk Thatcher, IIRC (who also played the punk on the bus and wrote the "I Hate You" song). The alien race was named as a salute to Mel Efros. But noone thought to mention it to him.
By the way, just for fun, the President's Efrosian consort was seen fleetingly in the trailers for ST VI - in a brief, cut scene from the final print of the movie:
Can you tell I'm procrastinating? :)