gray paint nightmare. help!

For months now, I've had tons of things ready to go into Jack's "big boy" room. Bedding, accessories, a headboard from Craigslist waiting to be painted, and a pretty good idea of the direction I want to take it. The problem? Well, apparently it's a bigger one than I even anticipated, and that means it's pretty big because I have delayed his room makeover for one reason. Paint. Such a simple word isn't it? Simple until you pick out a swatch, fall in love with it at the home improvement store, race home to get it up on the walls then discover it's all wrong! I didn't do that with Jack's room, but can you tell I've done it before? It's soooo stressful to me. So, I knew this time I'd do it the "safe" way. Tester size samples first, then buy the gallon(s) I'd need. However, I'm trying to find the rigth shade of (the dreaded) GRAY. It's not easy. I thought after seeing a few shades of gray look beautiful in other bloggers homes, I was ready to tackle finding the perfect shade for us. Wrong. I'm not ready. I'm aggravated. Stressed. And eager to paint! Instead, this is what I'm dealing with:

You can't even tell how bad it is in that photo. It's bad. Most of them look purple and obviously any hue of purple is unwelcome in the little guy's room. I can't even recall what color name each of those stripes are anymore but I did try a few I've seen on popular blogs.

Since I didn't use a large enough font and am completely frustrated with anything and everything involved in figuring out a paint color, I'll just list them from top to bottom.

-Gray Pearl by Martha Stewart (too dark???)

-Subtle Touch by Behr (too purple)

-Horizon by Benjamin Moore (a possible option)

-Windham by Pratt & Lambert (love love love it, but it's too dark for his low light bedroom)

All others unlabeled are too purple. The ones that look too dark in his room look just fine in this photo. The shade/color/hue I'm going for is similar to these:

via: Dreamy Whites

*note: that color on the walls? Gray Pearl by Martha Stewart. It looks completely different in Jack's one window bedroom because of the low light. :(

via: Life In The Fun Lane

*note: that wall color is Windham by Pratt & Lambert which again due to the low light in Jack's room is way too dark for us to use. :( :(

So you get the idea. A light, true gray, to show slight contrast against white trim and white furniture. Right now I think I'm leaning toward using "Horizon" by Benjamin Moore since it's light, and NOT PURPLE! If anything it has a blueish hue and I have various shades of blue accessories to use so it would work.

I'm signing off to tape off around the trim and window then I'm going to get ready to head out to buy paint. So anyone who has opinions and recommendations, share quickly! I need all the help I can get and I know here is the best place to find it! :)

*EDITED TO ADD*:

I went with Horizon by Benjamin Moore, thanks to a quick email back from Maria who had used the Martha Stewart color "Grap Pearl" in her home but agreed it could be too dark for a room with only one window, and without knowing I was considering it, mentioned liking Horizon. So, that's what I have two gallons of waiting to be opened. Juast as soon as I get back from Home Depot with a "sureline edger" in hopes of making "cutting in" go ALOT quicker. Once the little guy is in bed (my bed since I'll be painting his room), I'll have paint roller in hand transforming his cream walls to a lovely gray. Wish me luck!