Take this with a grain of salt, as I've never made a bargello, and I'm not so hot with choosing colours myself...
I feel like many of these blues are in the same "value". They're beautiful, they look nice together, but I don't see a whole lot of contrast, and I find with bargellos, they really give more of a "wow" factor, along with dimension and movement when there is more contrast added to them. Drastic darks and lights along with the more subtle colour/tonal changes.