On
GW's website, I like the Zahr-Tann scheme. What I went for with my Eldar was similar to the Alaitoc scheme, though I used Purple as the main color and Black as the secondary with red and gold as minors. The same pattern using mild oranges or browns would look pretty cool in my opinion.
Here's a
WIP sample of an early Vyper from when I started my army, maybe it'll give you some inspiration. Sorry my photography is pretty lousy. Hope this helps