Do Balrogs have wings? What Color is Legolas's Hair? What is Tom Bombadil? Entwives?

[Galin]

Originally Posted by Galadriel

I thought Thingol had silver hair? And Thranduil clearly does have golden hair.

Yes but the Sindar are rather sweepingly described as dark-haired, both in Appendix F (included as Eldar), and in Quendi And Eldar where compared generally to the Noldor.

There will be exceptions, but the usual colour -- or at least the colour Tolkien employs in very general descriptions of the Noldor and Sindar as a whole (the Eldar of Middle-earth) -- is dark-haired.