But the store did have a variegated yarn that was made to complement the original yarn I used. It contains the exact color of the original yarn, along with additional shades of blue. This is the back of the sweater with the neckline knit in the variegated yarn.
I can't decide if I want to keep the neckline variegated or not. I need to rip out the part that I've already knit on the front:
...and rework it with the variegated stuff. The places I found that sell this brand online don't have this color. I've found ONE person on Ravelry that has this in her stash. I sent her a message asking if she'd like to sell me a hank. We'll see what happens.