Hair Color and Beards

[Arothir]

I have been thinking about this for a while and we have certain things that are kind of assumed that I argue could be false. And these are the the fact that I would argue that Gil-Galad is blonde (see caveat below) and that Theoden did not have a beard and would very possibly been dark-haired instead of blonde before turning gray.

On Gil-Galad
This is based on the argument that he is the son of Orodreth (If he was the son of Fingon, then he was likely dark-haired, not trying to start that debate, but operating from the basis of him as the son of Orodreth as a given). We see one trait that tends to breed true in the children and male-line descendants of Finarfin, that they are blonde. As such, I would argue that an accurate depiction of Gil-Galad should show him as blonde. While in this case his mother was a Sinda, elven genetics do not appear to operate the same was as humans do where dark hair is dominant.

On Theoden
One thing we know is that Aragorn, Boromir, and others with significant elvish ancestry (which in reality is not a ton given how many generations separate Aragorn from the last infusion of elvish blood into his family through Elwing and Earendil), is that they cannot grow beards.

We also know that Theoden's mother Morwen Steelsheen is a descendant of the Princes of Dol Amroth, and likely counted amongst those with significant elvish ancestry. I doubt that her marrying into the House of Eorl would overide this and, as such, suggest that Theoden very likely was beardless. The second argument of him being dark haired is more based on an educated guess. Morwen means Dark Maiden, so she was likely dark-haired. As it would be reasonable that nobility would normally marry nobility, it is a high likelihood that Morwen carried two copies of the dark hair allele and regardless of how blond Thengel was, their children would all be dark-haired.

Whether or not Eomer could grow a beard is questionable, though I would argue that Elfwine could not given Lothiriel reintroducing more elvish blood into the family.

[Silky Gooseness]

You know, I fully thought this conversation would be about dwarf beards -! As these don’t approximate to natural human colours, with some being blue etc (unless they make use of dye)? I guess there’s no reason for us to believe other non-human beards follow the same rules. (And human beard hair doesn’t always exactly correspond to the hair on the human’s scalp).

The main bearded elf we know is Círdan, who is described as having a long beard, but also being “grey and old”. Does this mean that the greying is with age? as opposed to having naturally silver hair?

Tolkien says that it’s characteristic of Elves to be beardless, and then refines that it’s the third cycle of life where Elves are old enough to grow beards, assuming they want to. So would a beard always be grey, because it’s such a signifier of age?

Your point on genetics is interesting. I will think about it further. There’s the house of Finarfin, as you say, predominantly fair-haired, the dark haired Elves, and the red-heads. Could we track through the known family trees to see how it crops up? hmmm

[Arothir]

I think that is a great question on elvish beards for the color of Cirdan's could also be the fact that he was a kinsman of Elwë and Olwë (and by extension Elmo) and he could have had gray/white hair from the start, as Elwë and Olwë both had very pale hair.

For the fairhairedness, Nature of Middle Earth does note the following: "Only Finwë's second son by Indis had fair hair,* and this remained generally characteristic of his descendants, notably Finrod. Elwë and Olwë had very pale hair, almost white. Melian was dark, and so was Lúthien. * That is, Finarfin, father of Finrod Felagund" (The Nature of Middle-Earth, 186)

Also there is a note on the same page that in a typescript from 1969, it is noted that the name Gil-Galad was given to him, in part due to the radiance of his silver hair.

That being said, literally on the next page my theory on Theoden was wrong, though I am a bit shocked. While it does note that Tolkien "imagined Aragorn, Denethor, Imrahil, Boromir, Faramir as beardless. This I said, I supposed not to be due to any custom of shaving, but a racial characteristic." (NoME, 187) an asterisk below does note, "Men normally had them [beards] when full-grown, hence Eomer, Theoden and all other named. But not Denethor, Boromir, Faramir, Aragorn, Isildur or other Númenórean chieftains." So it makes you wonder how much of said chieftain heritage was needed to prevent beard growth.

[Arothir]

It is also important to note that Mahtan, father of Nerdanel, was bearded despite not being ancient, which I presume also matched his hair. Do we have any records of elves' hair graying with age? I do not believe we meet any other elves in the third cycle of their lives outside of Cirdan.