Thanks, Hockeymom... I ended up buying a sample from the hardware store of Pelican Gray, but it appeared too silvery blue. I think i'm going with Harbor Gray. like the shade, but slightly drab . Do you happen to know how much a difference in depth of color it would be if I asked for, let's say, 75% of the color and 25% white I guess? Do they do that? I seem to remember doing that years ago. Really don't want to spend another 7 bucks on another sample.

Ask the people at the PPG store.

I’m curiously what you ended up doing! I’m painting my home classic gray and had a designer suggest doing the same for our angled ceiling. Did you use classic gray all the way up?

I don't understand. You want griege, which doesn't work w/the tiles (as you have encountered). You're choosing colors that have too much gray in them. What's wrong w/Loggia or Shiitake? I think either of those would be great w/your floor tile. similar to Balboa Mist, but has more of the yellow tones to it. Or, have you tried these? You have a dominant tile floor. if you don't want to match the tone of the tile, then choose a contrasting color. (blues/ greens, etc) But to try and force a certain color range to work in that spot is silly. However, here are some of those tones you like. maybe you can find one. if you lighten the grout in those tiles, you may find certain colors work better. Grout Renew