Did a Google image search on that pic and came up with Mystical Blue by Benjamin Moore. You may want to cross check that with a BM color sample from a fan deck though.

It looks like a light blue on my computer screen. I know that is of no help to you, but it's impossible to tell what color it is from a computer monitor or a printed page. Even if you were to find out the EXACT color, it most probably would appear different in your home in your room due to the differences in lighting. Indeed you will perceive the same color differently in different rooms of your home depending on the other colors in the room and the way the light hits it at different times of the day.

The best you can do is get a fan deck and try to match what you see on your screen. Even then it will be difficult, and you will need to place a large sample of the color in your room to see if you like it.

Or you could hire a color consultant who is an expert in color to help you achieve the look you like.

Good luck!

Good advice Diana. If truth be told the colors in these beautiful rooms are really not that accurate. You have to find a blue that reads well in your space and may not be this color at all. It may be a good thing to not know the actual color; you could be disappointed!