I do not like white grout it always discolors IMO but if you want help at least post some pics of the space and the tile

Arctic white is supposed to be a pretty bright white. Are you looking at it next to your tile selection? Maybe it doesn't look right in a showroom, but have you looked at it in your home, with your lighting? In my experience, showroom lighting is not like home lighting. If you can't bring it home, at least walk outside at the store to look at it in natural light. Can you post a picture of them next to each other?

I have Avalanche and it has not yellowed over 8 years time.

TY! Is it a warm (with a little yellow) vs. a cool white? I just ordered some Mapai grout sticks to help me especially since I have a few floors to do as well.

they all dry lighter than the samples, but definitely will give you a better idea.