I have light grout in our floors and 2 dogs and 2 kids. Get the DARKEST grout that looks decent--and if it tends to be more grey/brown, get that one. I LOATHE taking care of the grout in our house. It needs resealed, but I keep holding out for having someone come here and take a jackhammer to it!LOL Even when it was sealed fine, I still had to take a toothbrush to it to get the dirt out.

Thank you bahacca for letting me know since I have four little dogs ranging in size form 4 lbs to 8.2 lbs that run in and out the sliding door to potty with me there but they may be tracking in mud and snow. I just love the way light grout looks and I guess you did also. Even if it is sealed, it will get dirty?

If you use epoxy grout, it won't stain and doesn't need sealing. The grout is initially more expensive and a PIA to use, but worth it in the long run

Thank you remodelfla! I also loved the picture of your kitchen with those beautiful neutral tiles!

Hello Lynn,
If your SpectraLock is staining, you've got an issue with prolonged exposure to acids or some caustic cleaner. Bleach, perhaps? SpectraLock epoxy grout has gone through several versions since it's initial release and the versions previous to the current one were all advertised as "Stain Resistant" by the manufacturer. The current version is claimed to be "Stain Proof", and I have heard of no other installers who have cared to challenge that claim yet.
Without seeing your tile, it's impossible to suggest a grout color but I will share with you that there are brands which I prefer over others and brands which for various reasons I try to direct my clients away from.
Laticrete's Permacolor is my favorite to work with. I've never had a color issue and the manufacturer has always answered my questions in a timely and thorough fashion. I understand that Custom Building Product's PRISM grout is also dependable, but I've never used it. I don't like Custom's Polyblend grout though as it rarely cures true to the samples I show my clients, regardless of the precautions taken. Hydroment and Mapei grouts are easy to work with and tend to cure true, though I don't use them often due to my client often finding other color pallet's more useful. TEC grouts perform well also and they've had some colors which fill needs that other brands could not. I've had one experience with Ardex brand grouts and I've thrown away that sample box and will refuse to show their product to any other client in the future.
As far as epoxy grouts go, two characteristics which bears mentioning is that since it's a resin-based product the final cure can sometimes look "plasticky" and there is a faint chance that people with sensitivities to epoxies will still react to the cured product. The later point is mostly important in bathroom areas where clients might be walking around with bare skin in contact with the epoxy, with their pores open and receptive to contamination from hot showers. It's an improbably complication but I always ask my clients about their chemical sensitivities if we are considering epoxy grouts.
Best of luck,
Shaughnn