Hi!
If I can jump in the conversation, I would say that it is a "sky" blue... Looking at the quilt, it is used in several blocks where sky is - background of the House block, in the Mayflower Block, as well as the Tree block. And it also looks like sky on the border... Of course, if you decide to use the same blue throughout these blocks. From my computer, it looks like a very pale turquoise (not too green either).
Andrée