I'm not an expert but when choosing paint colors, I prefer contrast. I would get a few samples and paint some spots on the wall to see what works the best with your tile. If the tile leans more towards white I think a soft sage color would be pretty with the elements you've described, but if your tile leans towards a brown, it's hard to say. If you can post pictures, it would really help.

I would start with your lighting. What kelvin bulbs are you using? We used SW Alabaster in my daughters house. It is the main wall color throughout but she has mixed it with gray accent walls in her kitchen/dining room. All ceiling, base and door trim is SW Extra White. The kitchen cabinets are an off white and island is dark gray with white subway tile. The Alabaster looks fine in her house and doesn’t appear yellow like yours though that can be the photo. It’s difficult to capture the true color. I do know we had to change from her initial gray choices as they were way off once we did samples and checked throughout the day with different light. Once you try different bulbs, I would ask your SW store for a paint deck to bring home to choose several to get samples. I always paint samples on large panels and move around in different light. You might also go to a tile store and check out sample boards. Google the term “grays that go with SW Alabaster” and you’ll find many colors go beautifully with Alabaster. Can you take another photo further back so we see more of the room? What rooms are adjacent?

Try Romabio. It's lime-based and has an old-world look or Farrow & Ball in their estate emulsion -- lowest sheen possible and it's clay based for that plaster look.

any grey in a dark room is going to make it darker / drabber. have you tried white? it might wind up looking like the grey you want in that light. however, if you have your heart set on actual grey and you can't find what you need from a paint chip, you'll need to go custom. go to a paint store (not lowes or home depot) and ask for color assistance. they'll have a bigger selection of color chips, and you can ask them to make anything lighter for your sample paint.