Wow, this is a bit of an old thread. Rereading it has kind of made me want to try drawing a ginger Tirian again....
Okay but I've noticed that in a huge majority of books from the mid 1800's to mid 1900's, unless for some reason it's very, very, very important to the story somehow, regular brown hair isn't mentioned because it was apparently that common.
As concerns characters, I think I generally think of Peter as having a kind of medium brown (or that kind of brown-blonde) hair that would get lighter the more time he spent in the sun. It's a bit cheating, I know, because it lets me picture him with pretty much any shade of brown, but it's a thing that could totally happen.

Interesting, brown just being taken for granted like that.
Is it really cheating if that’s really how you imagine Peter, though? 😉

Okay but I've noticed that in a huge majority of books from the mid 1800's to mid 1900's, unless for some reason it's very, very, very important to the story somehow, regular brown hair isn't mentioned because it was apparently that common.

So, we can assume they have brown hair if it is not mentioned?
This is getting off topic, but how important is it to even describe hair and eye color, etc for characters? Is it better to let readers assume your main character looks like them?

I just can't see Edmund as blonde. His personality doesn't fit it but oh well.

So, we can assume they have brown hair if it is not mentioned?
This is getting off topic, but how important is it to even describe hair and eye color, etc for characters? Is it better to let readers assume your main character looks like them?

I dunno, I just kind of do personally. Brown has a lot of variety, so I generally assume everyone has brown hair until I'm told otherwise (unless I saw fanart with a different color first).
As concerns your second question...that's a good point. Half the time I describe characters gradually but try not to make the same description more than twice over the course of the story unless it's really striking or important. I usually don't picture characters as having my eye color or hair color (except I indulged myself in imagining one relatively barely-described Tolkien character as having a couple of similarities to me, mostly so I could use myself as reference when I'm drawing him), but now that you mention it...that's like...an oddly clever way for an author to let the readers kind of slide into the story. "Sure she could look like you, since I never say the color of her hair."

* me over here taking notes cause I'm an amateur writer*

@Hermit: Narnia may have forced me out of my childhood dependency on authors painting pictures for me, or at least it was a major stepping stone in that direction. I grew up with books that pointed out things like hair colour, so when I got to Narnia and Lewis left all kinds of blanks, I had to come up with my own pictures. Which is why it kinda bugs me that he waited till the end of LWW to tell me Lucy was blonde. Either tell me early (like Shasta) or don’t (like Peter).
Is it important? Depends. Maybe the author wants to leave it to interpretation (like Lewis part of the time). Maybe the author wants things just so (like Tolkien all the time). Maybe it’s not a big deal that Caspian’s not blond in the Walden movies because it’s not important to the character or plot or world (unlike Trumpkin the very specifically Red Dwarf, or Shasta, who needs to stick out like a sore thumb in Calormen, or Puddleglum because nobody has ever heard of a Marshwiggle before).
So it just depends on how the author and the audience like things cooked. In other words, it’s very, very subjective. 😀

This is an interesting topic for me right now because it's one of the topics I've been pondering in an attempt to create some sort of writing advice series for beginning Narnian writers (I have no idea if anything will come of that). I also noticed how little Lewis gives us, but for me it was kind of the default because I was reading Narnia from an early age, and among the other books I was reading were Swallows & Amazons where, if I remember correctly, we're rarely if ever given those sorts of decriptions...
It's interesting what you noted about brown maybe being the default, though, because as I was thinking about the books I was reading in my childhood, I remembered some 19th century ones where the author would go into lots and lots of detail about the characters' appearance... but very often left off the hair colour. And when he didn't, it was usually black or blonde. Or ginger. Or grey. 🙂

Some characters in Narnia have hair color described and some kind of leaves you to your own imagination.

In many artwork I've seen of Queen Swanwhite, her hair is fair. So it wouldn't be out of the ordinary.

Anradin Tarkaan was described as having his beard dyed crimson, though it's possible he still had dark hair, like Calormenes were known for.

It's possible that Lasaraleen had dark hair as well.

Rabadash could have dark hair as well.

Miraz may have either red or fair hair, like his wife or nephew. It's hard to say.

Tirian would most likely would have fair hair, if it was a gene.

Rishda and Emeth both would have dark hair, since they are Calormenes.