Benjamin Moore's Dark Pewter is a similar color.

Floating shelf systems have interior mounting hardware that enables them look like they are floating. It involves hollowing out a portion of the shelf and then having a mate affixed to the wall — almost like two puzzle pieces. I am sure that something very similar is done here.

If you are adventurous, you can attempt to make floating shelves yourself, or there are plenty of styles that come with all materials and instructions required.

Thank you, I really appreciate your help!

Ikea have them

I'm amazed these shelves carry the weight! I know what books weigh, having a lot of them.

Beware the Ikea shelves like these - not very good (does Ikea still sell them?). Have a good and experienced carpenter build these for you as there are tricks to making sure they stay in place and don't sag.

Yes, IKEA still make floating shelves (not corner shelves like these) and they're pretty much useless - definitely won't support the weight of books such as these.

The shelving and cabinets are custom. The chair you can find here: http://www.allmodern.com/Herman-Miller-%AE-EA33-HML1088.html

Great look and awesome organization, thanks!