With the pattern you're doing, and I assume this is a backsplash, I've found that this is one of the few tiles you can pretty much "stack" without spacers and you'll have about a sixteenth inch joint...although you can certainly use wedges or spacers to keep things consistent.

Bear in mind that you DO need to space the tile 1/8" off the countertop as there will be "micro" movement between the change-of-plane there and this area should be caulked with a color-matching silicone caulk, NOT grout.

I suggest you wipe a sealer lightly over the tile after installation, but before grouting. I like an "enhancing" sealer as it makes the colors "pop" a bit. To see what this looks like, wipe a damp sponge over some tile....that will be the result. If you don't want that, just use a good, penetrating sealer as opposed to a penetrating enhancing sealer. DuPont's "StoneTech" product is one of the best around.

Once you've taken this decision, choose a grout that is darker than the lightest and slightly lighter than the darkest color tile. Hard to go wrong with this method. With joints this small, you need to use an "unsanded" grout, bearing in mind that all the little pits or "inclusions" will be grout-filled at the end of the day. Be sure to clean out the bottom line on the counter before the grout sets up. A small, stiff brush works well for this.

Let it set for at least a day and re-apply the sealer over everything.

Finally, caulk the line where it meets the counter.

(Edit)~ My Bad....just realized this IS a floor (duh)!

Forget what I said about caulk. Also, I would bump up the grout lines to a minimum of 1/8" or even 3/16." You will ALSO need to use SANDED grout as the unsanded is weaker, tends to shrink and the sanded will hold up to foot traffic far better.......

This post was edited by StoneTech on Wed, Jun 11, 14 at 11:39

Ok, thanks all the advice StoneTech. I won't be doing the install but I do have to pick the grout color.
Also, there was one thread on GW in which several people reported having the grout dry two shades lighter than the samples. Have you heard of that?

All the time. Has happened to me as well..... Some things that cause it would be, mixing with some well water with a high sulpher or mineral content, (distilled water is best...and cheap) using too much water in the "mix" which dilutes the colour, using too much water on the clean-up (same reasoning), certain colors from certain manufacturers seem to have this problem more than others, Custom from HD comes to mind, cleaning the floor with harsh cleaners is another...only use a neutral PH cleaner for this, or just medium hot water.

Rather than a standard, sanded cementatious grout, you might consider a "premium" grout. The Gold Standards would be Epoxy Grout, Urethane Grout, among others. My particular favorite is "Fusion Pro," available at most Home Depots. It is a pre-mixed, single component product. The downside is that it's pricey and only available in limited colours.

Choose wisely, grasshopper.....

Thank you Master Po