Have you also tested the colours on the other walls? They may look very different from wall to wall. Would only paint below picture rail, but I think that's your plan anyway?
I'm drawn towards the darkest one, the one on the left in the photo, but I like the lightest one too (the one on the right). Wouldn't paint the tiles.

Actually, the "brick" looks like glazed tile to me--hard to tell from a photo. I would paint the woodwork on the fireplace white and go with the darkest grey. It looks like you have plenty of natural light--is that a bay window?--to support the darker color. What color will you furnishings be? That would determine the shade of grey to go. If the furnishings are light, go with the darker paint. If they are dark, go with the lighter color.

the lighter for sure also check pewter cast from sherwin

Love the floors, BTW, lots of character. This looks like a Boston triple-decker house!

One more thing--just make sure you seal the floor with poly, so you don't get any staining from spills or water damage.

I can just see a beautiful, big, lush, green, Boston fern in that fireplace for the summertime...

What is that blue floral print hanging on the moulding? Is that wallpaper or drapery fabric? If so, the grey might need a little more bluish tint to it.

I disagree. It looks to me like the ceiling might be a ten-ft, which would be OK in my book. Or could be painted a very soft color grey, lightest possible and still be grey.

I like the paint on the right best. Would not paint the tile.

I am with the majority and the lightest one for sure. looks great

Thanks everyone for the input - the tiles are brown glass, not brick... We weren't planning to paint above the moulding/picture rail. The blue-ish wallpaper sample was something we were trying out but don't think will use.. Yes it is a bay window so plenty of light. I guess our main concern was whether the grey would go with the brown of the fireplace/tiles....

I vote the lightest grey too!

Lightest grey would be great in this space

You can tie the brown and grey together using your other furnishings. But, in any case, both brown and grey are neutrals, so they go together.

They all look great.
But the first one looks the best to me...

Go the lightest one- The dark grey is very cold ,reminds me of a prison cell!

Light gray so that it doesn't look like a garage wall. I love gray!

This post is a year and a half old!

Whoops ! I wonder what colour they went with....?

HAHAHA lol same!

surtout ne pas peindre les brique de la cheminée!!!!!, sinon pour le gris, le plus à gauche pres de la fenetre c'est ok

Go for the lightest one. Light grey walls feel crisp and airy.

This is what it looks like now! We went for the lightest grey.

amazing - well done...that looks great!

looks great! I'm glad you didn't paint the tile on the fireplace.

Good call on the light grey - it looks great

The light looks awesome. Thanks for the update!

It looks great now. Well done. :)

Looks fabulous! I love grey with wood tones. I think grey makes wood look rich. The grey also looks good with the tile, which I'm glad you did not paint.
Good job!