: : : : According to JRRT the Vanyar, the fair (in the sense of colouration) Elves, are blond or golden haired, no color, that I recall, is given for their eyes.
: : : : The Noldor are dark haired with grey eyes; some who have descent from the Vanyar are blond (it is never said that Glorifindel is descended from the Vanyar but he is blond); some are also described as having dark red hair.
: : : : The Teleri/ Sindar are said to resemble the Noldor in colouring (ie dark hair and grey eyes); those akin to Thingol are often (but not always) said to have silver hair and Thranduil a Sinda lord is said to be goldenhaired.
: : : : AFAIR JRRT does not describe the colouring of the Silvan Elves they are, however, related to the Telerin branch of the Eldar (through the Nandor) and it could be presumed that they resemble the Sindar.

: : : I think that in the Third Age the Woodland Realm of Mirkwood became a "melting pot", inhabited by Nandor, Avari, Doriathrin, and some Laiquendi and Falathrim; and that they were collectively. As for Thranduil's golden hair, as I've said before, was probably either dyed, a freak of nature, or a mistake on Tolkien's part.

: : When I say "collectively" I mean that they were called Wood or Silvan Elves collectively, I just forgot to finish typing that sentence.

: The 'Doriathrin' and 'Falathrim' are Sindar, while the Laiquendi are Nandor initially. Thus they are Telerin in descent. 'Of The Sindarin Princes Of The Silvan Elves' in 'Unfinished Tales' gives alot of information.
: I just reread the 'Lorien' chapters of the 'Fellowship of the Ring' and must now partially amend my above statement that JRRT did not describe the Silvan Elves. As Haldir brings the members of the Fellowship to the river and ropes are cast across to bridge it, an unnamed Elf on the other side is described as golden haired.

Okay, okay, I was wrong...