I'd go with a 4" tumbled marble. You can be pretty creative with it and the contrast gives a bit of a "Tuscany" look. It ranges in colour from a light almond to the "Scabas" which has more and deeper colour variation..

I don't know what kind of look you are going for but I used this tile with my Verde Peacock granite which is similar to Uba Tuba. You might be able to find something similar. I bought it at a local tile store but I did see it available at one online source. I chose to do it vertical but you could run horizontal under your cabinets. It is definitley a more contemporary look though.
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Here is how it looks in my application:

Here is a picture of my Verde Peacock (pretty close to Uba Tuba) and my backsplash. Not the best pic, but you get the idea.

Fire and Ice backsplashes come in green tones as well as the grey slate ones. Google and you will find examples. I think this would look amazing in your kitchen.
For a more simple feel, I would try to find a green tile.
Playing it safe, the above beige tile ideas would be good too.

Jeffrey Court has a green Fire and Ice that will go with Uba Tuba!

I have uba tuba, but with cream colored cabinets so I chose a combo of cream subway tile and beadboard.

If I had cabinets that were the same as yours I would probably choose a tumbled marble or traverine.

If you are planning on painting them I might do something different. Choose your paint before your backsplash. I think a sage green island and tan cabinets would look great with uba tuba. I would probably do a 4" slate tile then.

I have always liked this combo. It is Sumi-e large brick.

Here is a link that might be useful: sumi-e

I am a little late here, but I have fire and ice with uba tuba and cherry cabinets. Let me know if you want to see a pic