Primed room. Selected Behr Sonata blue 530E-3 and thought it would be light enough. Seemed the best match with other finishes going in. However, it is going on much darker. You'd think I'd know better by now, I usually don't make these mistakes. On the other hand, I'm quite talented at second guessing myself.

My idea: Paint the whole room (now that I'm in) and then go get the same color in a much lighter amount of tint. How do I tell HD?

My bathroom before we gutted it:

New cabinet. Sorry, photo is a little grainy w/out flash, when I use flash it makes the cab look orange and really it's more a cherry undertone.

My granite. IRL, Sonata Blue paint I picked is very close to light blue in it)

However, I think perhaps right now you're reacting to the dramatic switch from white to blue. I bet it will look more like your vision once you finish painting. If not, and you still think it's too dark...at least it's a small room! If you stay in the same family and just go a bit lighter it shouldn't be hard to cover, either. Another option if you feel it's too dark it to paint the ceiling back to white.

I think it will be okay and we will definitely wait until it dries and take down the tape and covers to get better feel.
My husband pointed out that one of our light fixtures is not in the room right now, and the lamp I have instead does weird things with the light. I will check in with the kids for their opinions...in the end it's their bathroom primarily.

I hope it's coming out as you'd planned! :)

Husband had to install the cabinet for granite templating tomorrow. I could still paint but if I do repaint, he has requested I get it done before the granite itself is in, which gives me until Friday AM.

Am going to go to the guy who's good at Benajamin Moore tomorrow. It is a longer commute to go there than some of the other paint companies.

I will try to get a pix up early tomorrow AM. Hosted houseguests and Easter dinner. All good stuff and my kids got a chance to hang out with some close family friends but I'm a little tired.

One trick I've heard to avoid picking a "baby boy blue" is to pick a gray that leans blue. My coworker used Ace Dover Gray in her bathroom and said it looks like a waterfall. My brother used Ace Silverton and it looks like a silvery blue (with dark wood vanity, wish I had a pic to share). Clark + Kensington Lucky charm might work, too, unless it's too dark.

I bookmarked the following link because it helped me decide to use BM Sailcloth color in my living room, but you can scroll down further to see BM "Pale Smoke" in the bathroom, another gray leaning blue.