In J. R. R. Tolkien's fictional universe of Middle-earth, the best known Silvan Elves are the Elves of northern Mirkwood and Lothlórien. In the First Age the Elves of Ossiriand, or Laiquendi, were also referred to as wood-elves.
Silvan Elves (more properly called "Tawarwaith") are of Nandorin descent but also mixed with Avari, Sindar and Noldor and governed by Sindarin rulers. Examples of these rulers are Thranduil king of northern Mirkwood, Amdír, and his son, Amroth, the last Sindarin prince of Lórien before the rule of Galadriel and Celeborn (of Noldorin/Telerin and Sindarin descent, respectively).
According to notes made by Tolkien after the publication of Lord of the Rings and found in Unfinished Tales, Oropher, the Sindarin king of the Silvan Elves of Mirkwood, or Greenwood the Great as it was then known, raised a large force as part of the Last Alliance to overthrow Sauron. During the first assault on Mordor, he disregarded Gil-galad's tactical plan and led a reckless charge in which he was slain along with two-thirds of his troops. Rule of the Silvan Elves and field command of their remaining strength passed to Oropher's son Thranduil, the father of Legolas.
Legolas of the Fellowship of the Ring, although he lived among them and presented himself as one of the Silvan folk in The Lord of the Rings, was not one of them. As a son of the Elven-king Thranduil, who had originally come from Doriath, Legolas was actually a Sindarin Elf. This is complicated by the fact that a small minority of Sindarin Elves ruled the predominantly Silvan Woodland Realm of Northern Mirkwood, a minority to which Legolas belonged. The Sindarin minority in that realm, who should have been nobler and wiser than the Silvan Elves, can be seen as having "gone native" at the end of the First Age: after Morgoth was defeated and all of the grand Elf-kingdoms of Beleriand were destroyed, they can be seen as going back to "a simpler time" in their culture.
In the 1977 animated adaption of The Hobbit, The Wood Elves are dipicted as having fair hair and pale lavender skin, with clothing predominatly brown and olive coloured garb.