I think it depends on the color of the walls and the bathroom. Often marble and white are paired with gray/blue/green cool tones. If you go with cream/tan/beige/gold or even something more bold I think travertine will be just fine. The white and warm tan will go very nicely together particularly if you toss in some dark brown (accent tile? vanity? vanity top?)

I know it's beadboard not subway tile, but look at this bathroom. It's got a similar color structure. If you did white subway halfway up, I think it would look great.

via this blog

If you like travertine, what you might look into to go with the white subway tile is silver travertine. I'd bet it'd be an awesome combination.

Great pics, thanks. Bill, at a recent visit to a tile shop I did see silver travertine and I immediately thought what a great mix between travertine and marble, so it is definately an option.

Sandn -- Love your bathroom look. The tile is so clean and fresh looking. What subway tile did you use? I love the trim tile off the floor, it really breaks up the wall and is a great detail.

Brickton -- that is a very similar look to what we want. We are having a white vanity built that will look a lot like the Pottery Barn Newport double vanity, but it will be a little more contemporary looking. To warm it up we're going to fabricate a wood counter using either butcherblock or reclaimed wood. Every contractor has bristled at this, but our cabinet maker said he's doing a lot of reclaimed wood vanities and I think it will warm up the space.

Thanks again for the responses, if you see anything else send it my way.

Abd1,
Thank you. We never tire of the clean look of the tile. The tile we used was originally purchased from Country Floors in Toronto. They called it Highgrove. However, their Toronto showroom closed during the recession. We were hunting for more of the tile for our kitchen backsplash recently and we discovered that the manufacturer, in Sri Lanka, has closed down (probably and sadly because of the social unrest in that country). We were able to track down a supplier in California, and they still had quite a stockpile of this tile, which really is such a perfect basic subway, and were able to ship it to us.
Tile: Lanka wall tile (available in white or alabaster, but called candlelight when we originally purchased it :)

Whew! Sandn, beautiful bathroom! Since you mentioned grout colors, do you happen to remember which colors you used?

Sandn- I was wondering what hex tile and color you used? Timeless and beautiful. Can I also ask you how much the grout may or may not show dirt?

Nutherokie and Onelady, I don't want to take over Abd1's post, so I'll repost a response to your tile and grout questions. Link below:

Here is a link that might be useful: Hex tile and grout questions, answered