Study's have shown that blue is a good 'thinking' and 'awake' color for both children and adults. so I think the blue color is very good. I shouldn't worry too much the actual shade blending in with the family room as long as the blue you choose does regularly appear naturally in nature. So a more sky blue [and that is really a large range of colors to pick from] would do just as good, too. Since it is a kid's room, make it as gloss as possible as that is easier to clean. Gloss makes a paint color 'stronger' so take that into consideration if you get any blue and pick a bit of a tint under the one you want.

Now, here is something I've seen a few times and thought it worked really really well. Paint the ceiling blue! Everyone says, do it white make it look higher, but a lighter shade of blue 'lifts' the ceiling just like the sky. Of course, you can't really do this with a popcorn ceiling and you are stuck with the white, but if you have a paintable ceiling, consider that first, then ponder what the walls should be. Should you do a lighter blue ceiling check into doing clouds too. With a blue ceiling I would suggest a lighter greenish color for the playroom. That will merge nicely with the family room. Think something like the light pretty green from the first leaves of spring would be very nice. Back to blue walls. A dusty blue is nice. Various sky blues are nice. But if you got a light blue-green color that would also blend the two rooms together. Everyone thinks turquoise as a darker blue-green, but there are very very light versions of that color [they dream up new names for colors every few years]. Sometimes they call them sea blues/sea greens. Whatever color you do use on the walls — dusty blue, sky blues, blue-green blues, — let it be lighter in color than you would choose for a normal room because of all the brighter contrasting accessories. You don't want your walls conflicting with the rest of the furnishing, you want it to create a pleasant backdrop for everything else. [and have something that won't clash with the changes that will occur in the kids room as they grow.]

Now if you really really want to drive yourself crazy, you can create a nice effect in the kids room by painting the walls different colors of blue. In the same blue family of course. But like one darker wall, and the rest a much much lighter shade in the same blue family. Again, keep in mind the molding [I hope it isn't painted tan]. I'm sure you've seen this a lot, a really really gloss color on the bottom half of the wall and a matching lighter non-gloss on the top half of the wall. [you don't need a molding piece, just the ability to do a decent straight line]. If the room is small I wouldn't recommend it. Do try to take into consideration your kids are growing. Another good point for the high gloss [other than cleaning advantages] is that you can put those sticker things you put on windows for decorations, [not glue stickers, but plastic something] and those decorations will stay up real well. Plus you can tape things to the wall and remove them later without taking the paint off.

I think your color choice is perfect. I was honestly thinking of the same color before I even read what your choice was. Having raised 3 sons I think the dusty blue would be very nice. Since it is your kids play room, why not ask them how they feel about the color. I wanted to tell you also that I recently saw a commercial on TV that stated that there is a place that will let you get tiny samples of colors, I can't remember if it was Lowes or Home Depot but why not give them a call and see. I am going to do that the next time I re do a room as I have been stuck with gallons of paint because I thought a color I thought was great turned out to be not what I expect. I also like the dark tan, almost chocolate colors, the grays, or the deep golds. It is really an individual taste I think but I would try the small samples, look on the internet at rooms that are already done to get color ideas, and then decide. I think your furniture would go with almost any color. Hope this helps and Happy Painting!!