I'm stunned just thinking about the amount of work in your beautiful quilt-to-be! I like to play with Windows Paint when I'm planning a quilt, so I took the liberty of testing the colors you mentioned (I couldn't capture the entire quilt, but this should give some idea of that it would look like with pink, aqua or lavendar. I will immediately erase your quilt picture from my computer after posting, but I wanted to show you how easy it is to actually test a color with this digital tool that comes with Windows.
I don't have any opinion about which color to use, but any of them would be attractive. I would not care for a busy design with this, but maybe even that would work with a narrow inner border to provide a break.