How pretty!
http://www.ebay.com/itm/1995-Alembic-Essence-Koa-4-String-Bass-Guitar-8-4-lbs-/151889512998?hash=item235d520a26:g:0sAAAOSwkZhWTjK-

That is a looker. I wish these had fingerboard inlays. Wait, no I don't. I don't need the temptation!

I'll have to confirm in the file, but this beauty sure looks like Flame Walnut to me.

This has been on Ebay for a while and certainly looks like Walnut to me, too. Nice top.

This is one of my old basses. Actually this is the only one I wish i had back. I checked the serials against my records. I thought it might be my old one because I put those custom knobs on it. It is flame Walnut like Mica says.
 
Nick