Thanks Guivenere, I had already forgotten this thread

And yes indeed; "dûr" means dark...that was my bad.
As in the name Anduin, "an(d)" = long and "duin" = a (long) river. "Lin" itself means pool or lake as in Linaewen. That could mean that it's "lego" that means green and not "legol" if we all agree that "las" means leaf. I read somewhere in this forum a great explanation of Legolas' name but I can't find it