This topic and similiar ones have been discussed many times and have been indexed in our Haudh-en-Ndengin forum. Check out the
Huadh-en-Ndengin Index entry for
Legolas - Appearance -or-
Elves Hair Color
There you will find links to all previous discussions similar to this topic.
Since those topics are all quite old, feel free to continue the discussion here after you've read them thoroughly.