Hi Tim and if I haven't before....welcome to the Do-It forums.
I checked Spike-its page and MF's page along with lurecraft's and none have sapphire blue. It should be a color right along this one from Spike-It [https://www.ispikeit.com/product/257/ultramarine-blue-106] and also the fluorescent blue from right here at Do-It when using the stronger mix....more drops. You can adjust the depth of the blue by using a toothpick dipped short in a regular blue. This is a color I'd suggest doing without any hi lite, pearl or glitter being added until AFTER you are satisfied with the shade of blue you want.
Is there a particular brand of worm or plastic made in a sapphire that you want to copy? What it is? Most companies have a color plate so we can get a hint as to the actual use of the color.