So, I decided it was time to try some dyeing. I bought some blue and navy Jaquard Acid Dyes and combined the two for a dark blue color. I wanted to maintain some of the original tie dye quality of the fabric so I twisted the fabric and bound it with rubber bands. I used the instructions provided online for the dye process.
Again, during rinsing a lot of the dye washed out, despite using Synthrapol as a pre-wash and after-wash. I don't believe the dye was the problem, rather the fabric is very troublesome. As a comparison, I also dyed some other fabric (originally brown) which turned a solid dark blue.
Still, I like the dyed fabric much more than the washed out yellow. Next step is some sewing. I'm planning to make a dress.