I have a bathroom combination similar to that. My granite is Giallo Ornamentale. It's what Santa Cecilia used to look like (lighter). Don't think my travertine looking porcelain is "thru body" tho. Not sure. Below is a link to the new master bathroom. The diamond shaped tile on the walls is tumbled travertine. You can see how this porcelain looks next to the real thing. It's by Marazzi. The floor tile is a 20" tile.
Monica

Here is a link that might be useful: Travertine Looking Porcelain Tile

Ours is not technically through body, but does not have any drastic color differences when looking from the top and turning over the tile and looking at the bottom. If it were to get a chip, I believe it would not even be noticed. We bought it from Lowes and DH installed it. It has mostly creamy taupe
with some grey and a hint of brown. The size is 18" x 18" (not rectified). It's called Pietra Series-Bone. Grout is Keracolor U Ivory #39.

This isn't cheap, but it's some of the best in the world, and it IS thru body color:

Here is a link that might be useful: Graniti Fiandre Travertini Collection

Look at Crossville's Palais tile. It's supposed to be a limestone look. Lots of variation, through body, and it's won an award too. Download the Commercial PDF brochure at the site of room scenes using it. It shows the tile better. The small photo there doesn't do it justice. There are two light beiges. One golder and one more muted. Really pretty! Here's one of them. It's not as green as it shows here.

Here is a link that might be useful: Crossville Palais

We purchased 20" x 20" tile that looks like light travertine, and although we didn't use it, I may use some of it in our laundry room/office area is we don't sell all of it.

We chose the brand Legend and the color is Serena Blanco. I'm not sure if it is through body, but I was told it is rectified. We wanted little to no grout line. Not sure what city you live in, but you may be able to locate a sample through a tile store. It was difficult to get a good photo of it inside, so here it is outside. HTH.

Mannington's 'Botticelli' line is through body, and very reasonably priced [at least, at my local shop]-- under $4/ft.

{{!gwi}}

Only available as 12x12 and bullnose, plus the mosaic you see on the 'rug' above. Since the edges aren't 'eased' at all, it's easy to cut down to smaller sizes, though.

Here is a link that might be useful: Botticelli

You might want to check out peacockpavers.com. Someone suggested them on one of the flooring threads.

One point I didn't even think to raise until reading through some of the answers here-- that tile from Graniti Fiandre comes in sizes from 12x12 to 24x48.

Monicakm, do you know what your tile is called? I like it.

kelleg, thank you :) Ragno owns Mazazzi Co. I couldn't find the series, (on line) under Marazzi but did find it under the Ragno label. My store had the Marazzi label on it. Eclipse is the series. Moonlight is the color.
Monica