Maybe.
I don't really have any basis for this, but I tend to picture the Svartalfars as having a more East Asian coloration (some such groups tend to have skin much whiter than Europeans). I tend to think that dark hair and eyes are pretty much universal, although some may be darker than others. If I recall though, red hair is actually found in all human races (definitely among middle-easterners and Asians), although it is much less common and typically a much darker red among non-Europeans. I would not expect to find any orange-red or strawberry-blonde haired Svartalfar, but a deep auburn may be common.
Edit: What was I thinking? None of the Svartalfar shown have dark eyes. Their eye color always seems to be grey if the leaderheads are any indication. (There is however one region of China where grey eyes are reletively common, and the people tend to be extra fair skinned. That is probably because of interbreeding with the ancient Caucasian inhabitants of the region though. Blond hair even shows up there form time to time, although less often than red which still is not common.)
While most Ljosalfar look European, the description of at least one sounds like it could possibly be closer to that of a Native American or middle-easterner. Even after a couple months (or was it just weeks?) in the sunless Well of Shadows (first as a patron of their library, then as a prisoner), Talia still had a deep tan. (She also has dark ees ands also described as very curvy and voluptuous, not gracile like we usually picture elves.) Actually, I think Ljosalfar are usually described as being quite tan, unlike those Europeans who share their more common hair colors. I'm pretty sure that the skin of elves (of either court) is very smooth and even in color, not prone to freckling like the fairer European skin types. There are certainly redheads and strawberry-blondes among the Ljosalfar though, including their Queen.
(The Gossam brothers are known to have wrinkles instead of smooth skin, but time in and near the land of the dead may have deprived that group of the typical pristine youth characteristic of the elven race. Elves were men changed by their closeness to the Sucellus, but the Once Elves have not honored nature for ages, have abandoned the elven language in exchange for Patrian, and are more influenced by the sphere opposite Sucellus's new precept; their name may indicate that another change like that which created the elves has occurred and that the term elf does not really apply anymore.)