Im thinking that almost every fantasy world has some form of "dark elves" in it.The LOTR, the Warhammer, Warcraft etc...But differently from any other fantasy, dark elves in LOTR were never an "evil" ones.Can anyone tell me when did "dark" elves become "evil" ones?Here is a description of what dark elves are in middle-earth.

In J. R. R. Tolkien's Middle-earth writings, the Moriquendi or "Elves of Darkness" were a group of the Elves that did not join the Great Journey across the continent of Middle-earth and the Sundering Seas, and thus did not behold the light of the Two Trees in Valinor. The Dark Elves were in no way more "evil" than the Light Elves; the latter just had a surpassing knowledge and skill, and were more "noble" and potent. Tolkien was hesitant about the precise definition of the term; according to different writings, the character Eöl was one of the Moriquendi, as well as the Silvan Elves appearing in The Lord of the Rings.

And are there any other fantasy world, that does have dark elves in it, but just not the "evil" dark elves?