You'll probably find this an interesting ideabook (follow the link under the pic, also read the comments)
https://www.houzz.com/magazine/9-ways-groutyes-groutcan-add-to-your-design-stsetivw-vs~164114

I have a tiled floor and light grout. And a steam cleaner. Every now and again I clean the grout with the steam cleaner. Relatively easy to do and ever so rewarding ;-)

You can use the limestone tile and minimize your grout lines provided the edge is rectified (90 degrees). I would still recommend a lighter grout to blend. Darker grout will outline the tile and make it look busy. Try using larger format tiles say 18x18 or 16x16. Do the hallway in a diamond pattern outlined with tiles laid straight. Try using an epoxy grout. It will be stain resistant.

You can look at our projects and look at Cordillera Country Club as an example of the pattern I was mentioned above. It was done with travertine chipped edge and a marble inset.

Ive never been a fan of dark grout on light tiles. I prefer not to see the grout lines, so I stick with a fairly even colour so that they dont stand out. I've seen the dark grout done a lot though and it's really just a matter of preference. You could also try using an epoxy grout or adding some modified additives to sanded grout to help it stay true longer.

I also agree with Boerne Kitchens. I do use large format tile and keep my grout lines to 1/8"

I havent hear of epoxy grout...will it stand up to high traffic and mucky toddlers?

epoxy grout is the way to go.

Custom Building Products offers CEG-lite a 2 part epoxy grout that has the maximum resistance to staining and chemical changes. It has great color choices and though it is more expensive it is an excellent product. Mapei also has an epoxy product called Kerapoxy. Either of those would allow you to use a light color grout with less worry.

does anyone know how skilled a person needs to be to use it? we are undertaking a massive project and I am concerned my contractor is using less skilled people than i would like to keep costs down - this is the reality of our budget unfortunately.

Also, as for the Kerapoxy, if you feel the need to use epoxy, Mapei's Opticolor might be a better choice, especially with limestone, or another good choice would be Laticrete's Spectralock.

That all said, I still disagree with the use of epoxy just for stain resistance.

IF you decide to use epoxy grout, the installer should be skilled and have worked with it before. It is a bit harder to apply and tilers in our area charge us more to apply it.

following on from another comment then....the stairs in the hall will be painted white, with an american oak base and banister and instead of spindles...glass. I wants a bright, light space. The tiles will be used in the kitchen which is a painted almond shaker cabinets....what colour or finish flooring would you guys go for?

apologies for my grammar today too - sleep deprivation caused by same mucky toddlers.

Tiling is one of my most important phases in a project. You either pay more for a good tiler, or you stand by every stage of the tiling to ensure you are getting what you want. I talk out every detail with my tiler and then come regularly to check progress. I also insist I be called if there is any question or doubt.

Have you considered terra cotta tile and dark gray grout? Agree that light tiles and dark grout can look very dated.

These look beautiful but would probably be better suited to a more rustic house where as ours is probably going for a more classic meets contemporary style with the glass in the stair case....

Sometimes you can get away with mixing but not always. I do love this look -- it might be interesting. Nothing you mentioned besides the glass sounds too modern. Glass with toddlers--stock up on the Windex.

You won't save money by using less skilled workers. In the long run it will cost you much more.

"IF you decide to use epoxy grout, the installer should be skilled and have worked with it before. It is a bit harder to apply and tilers in our area charge us more to apply it."

This is one of the reasons why I don't like to use epoxy in residential settings, unless absolutely necessary, and I'll get to those times in a minute. A 25 pound bag of Laticrete Permacolor grout-- a newest generation modified grout which is said to be stain resistant, will cost you about 22.00, and cover about 150 sq. ft. of 12x12 tile. Now, if you go with a unit of epoxy, which will cost you about 85.00, and cover about 35 sq. ft., you can see the cost difference. And as Creative Innovations & Designs Stated, depending on WHICH epoxy I use (from something like Spectralock or Opticolor to one of the 100% solids epoxy, also known as commercial grade), I'll charge a premium of 1.50 to 2.50 per sq. ft. to apply it. So although it IS a little more bulletproof, it doesn't justify the tremendous jump in price.

Now, to get back to the times when it really IS necessary-- there are two instances where I feel epoxy is not only justified, but necessary. Those are 1) if you have pets that are prone to accidents-- even if you seal the grout, the ammonia in urine will eat away at the sealer, so you really should use an epoxy in that case, and 2), if you're tiling your countertop, you don't want meat juices seeping into the grout. You'll start a bacteria farm right where you prepare your food, so again, epoxy is really necessary.

There are a lot of installers who will tell you they ALWAYS use "X" in all applications. Each product has its use, and for those uses, it can be a lifesaver.

Creative Ceramic - thank you for this information - it is very helpful as I lean far away from epoxy right now.

Ditto! Creative Ceramics I appreciate all the helpful education and your dislike of the myopic "I always do X" mindsets which make me crazy!