I don't have any experience with Shale, but I just googled it and it looks like a fairly light color. You could try it at 25%, maybe? I am all for non-white ceilings; however, my honest opinion is that I see a lot of little white "things" up there on that ceiling (can't tell what they all are -- some are vents, others might be smoke detectors or something?) that might look like random white polka dots on a non-white ceiling. Do you know what I mean? I'm talking about the pic of the second story ceiling. So I guess what I'm saying is if you go with a color other than white, I'd suggest keeping it as light as possible so those little items aren't too conspicuous. Unless they can all be painted, too?

Thank you sueb. I will definitely be painting all vents the same color as the wall or ceiling that they are on. Benjamin Moore will put any color you want into a spray can which makes painting them very easy. One of the other white things is a very old light that will soon be replaced with a recessed light, the bronze colored light will also soon be a recessed light. The other white things are smoke detectors. I don't know any way of painting or hiding those.

I repainted my house which also has a two story foyer and living room and I painted the ceiling the same color and I am really happy with how it looks. Our situtation was a bit more complicated as we have rounded corners and couldnt really stop anyway. Regardless though, I think having the ceiling the same color looks more sophisticated and less choppy (and less of that builder grade look).

I'm not sure how dark shale is, the color we used was SW taupe tone at 40% and I'd say it's pretty light.

After looking up the color shale by bm, i think it is light enough that you could do all walls and ceiling with it.

Lyban, I think I'm going to go ahead and try it on the ceilings as well. It took me so long to find a gray/taupe that I like and the thought of finding another one that's lighter sounds awful. I just don't want to have to repaint it because I'm having to hire painters to do the ceilings.

Light colors can look much darker on ceilings because of the light angles, the different texture, etc. I recently went through a lot of trials to find the right color for a tray ceiling because the horizontal and vertical surfaces were so different. If 50% looked as dark on the ceiling as the 100% on the wall, I think you'd better test the straight color on your ceiling before you have the painters do the whole thing. You may want to go try 25% or even less, and in my case, I had to adjust color balance too.