Our tile guy had a palette of grout pieces. Even so, I struggled and posted options.
The tile guy brought a bag of my 2 finalists and we dry grouted a couple tiles for the final decision. My SIL and DH liked the medium based on the bars but made a unilateral (and FW fav) to go with the antique white.
We used a brand called Tec. Not sure where it fits in the spectrum other than the GC and tile guy both said it was excellent grout.
Most tile stores will have sample bars to use.
So exciting!

I don't know where you purchased your tile from, but since you are trying to match the tile color why don't you call them, or email them for their recommendation.

We used a medium brown color called Summer Wheat. A couple of things --

A colored grout will appear to be darker used next to a light tile than next to a tile that is close to the grout color in value

Many times the grout will dry lighter in the installation than the sample. This can be influenced by how the grout had been mixed-- how much water was used-- and even the mineral content of your water. Good idea to make actual samples with your tiles.

The store where we bought some of our tiles, "Best Tile," had a set of sample grout sticks (about 4 inches long) that they let us borrow. This was very helpful. We used TEC grout, available through our tile store and at stores throughout the country.

Some of the best advice we got was to use real grout on a sample board before making our final selection. For our sample, we had our contractor grout one row of tile behind our range in a place that would never been. seen. I am so glad we did that. We ended up feeling that the grout we had selected did not provide enough contrast. We quickly chose a slightly darker color grout (TEC "Pearl") and were very happy with the slight definition it gave each tile.

You've gotten great advice so far.
Don't trust the grout charts at the big box stores.. I agree that the plastic grout sticks (at our tile/laminate/flooring store) were much closer to the real color and more helpful. We used both TEC and PolyBlend throughout our house, depending on the exact color we wanted (mostly grays, but the undertones of the grays can really vary from one brand to the next). There are so many more options than what Home Depot and Lowes offers. The only hitch is that you have to wait for an order rather than grab it off a shelf.

You have such beautiful tiles! Can't wait to see them in and finished.

I've installed tile with Laticrete PermaColor grouts in two bathrooms and an entry way with no problems. I compared with Mapei also recommended by my tile store, but preferred the Laticrete colors. My brother used Mapei and has not said anything about it, so I presume he was pleased with the result. In all cases, the tile store loaned out either the full line of grout color sticks for the brand or just the handful I that seemed right. I found it important to compare the grouts in various lights (daylight, night time with overhead, etc) to find ones that worked for me.

For your backsplash tile I vote for the vertical cross layout.

i like the vertical too:) And I like'd like the grout to show a bit on that pantry tile to help the design stand out. Unless there is a beveled edge then I would think the shadow will help it stand out.

a2gemini - thanks. I've tracked down a local big tile shop that stocks TEC so will go tomorrow and get a few sample colors to try out on a sample board. Sample bars sound useful for narrowing down the colors.

localeater - don't want to match exactly, just want something that goes well with the CT, cabinets, and tile.

Thanks sayde, good points about the drying grout being a different color. I've also read that it may take several days before grout color finishes drying.

Francoise47 and rhome410-- We'll definitely do a sample board or two. Glad to hear all the TEC recommendations.

Pricklypearcactus - I always forget what a difference different lighting, makes. In this case, there are two doorways in the room but no natural light. We have two CREE overhead lights and lots of UCL.

chispa and enduring - my favorite is the vertical cross as well. I've looked at so many star and cross patterns and for a while considered doing the stars in one colorway and the crosses in another. In this case, grout color can be a third partner in the color scheme; I've seen some beautiful examples. But I chickened out and went with the single color (which should have variation in it).

Oldbat post some pictures with the grout bars.