@Patricia Aragon
I've installed lots of tile, often the grout colors most used are what is available on the shelves at HD. If you have a tile supplier near you, you can usually select from any of these Custom (brand) colors. From what I'm gathering, you might want to have a rule of thumb to help you select grout colors so you aren't mired in analysis paralysis in this process. These colors below work with a wide array of tile, and these seem to be the go-to grout colors for many home owners based on the desired grout's color family and shade.
Off-white, light: Antique White
Off-white, medium: Bone
Gray scale, light:. Platinum
Gray scale, medium: Delorean gray
Gray scale, dark: Dove Gray
Beige scale, light: Linen
Beige scale, medium: Haystack
Beige scale, dark: never had it happen, actually.
As far as stain prevention goes, just use an additive when mixing it up. Surface sealer used after install isn't as good, though it won't hurt. Some associates at home depot may recommend the "polyblend plus" (has orange coloration on the bag) because it has additive mixed in to the powder already and you don't have to buy separate liquid additive. But it isn't always DIY friendly as it sets up quickly and pretty hard, leaving a thick haze that can be difficult to remove, especially with rough textured tiles. A liquid additive like the following might be just the ticket:
https://www.homedepot.com/p/Custom-Building-Products-StainBlocker-32-oz-Stain-Resisting-Admixture-Additive-for-Grout-SBG32/202525433
If you're looking for an off-white grout, I would feel confident recommending either Antique White or Bone with the above liquid additive. Good luck.