the monitor makes your tile sample look green/gray, not white.

For me, when choosing grout, I prefer to match the tile as close as possible.

Avalanche is stark white (generally my go to) Moonbeam is softer with a gray hint.

Eggshell is an older color, I haven't used.

Try a bit of each and let it dry... see what you like, you can always go over what you sampled.

Your undertone identification was very helpful- Thank you! I forgot to mention that the floor will be an octagon and dot in white, which is also a softer white and the grout I decided on will be Mapei Warm Gray. It’s a tiny bathroom.

why dont you use the mapei warm gray grout colr for all

Avalanche

Thank you! I’m now leaning in that direction of having both floor and wall tile grouted in Mapei Warm Gray with the walls 1/16” lines.

If not, I could look into Laticrete to see if they might have a warm white that’s in between Mapei Eggshell and Avalanche… These different shades of white drive me crazy, lol!

I personally do not like ‘white’ grout. It looks great initially but tends to discolor as it will in your bathroom on the lower part of the shower walls

Frost

You're not doing 1/16 on lugged tile. It's physically impossible. And you should do Warm Gray for all. In Ultracolor Plus FA or Flexcolor CQ.

Thank you for your reply. I just looked up the term “lugged tile” as I’ve never heard of it before. Learned something new! Very good to know’