For the front piece, I cut from the graduated rainbow fabric.
For the back, I used the more random rainbow piece.
For the dyeing, I laid it on some other fabric to soak up the excess dye. I think it would work better with a 100% polyester fleece, but I need to buy some because I plan to use what I have on hand. I used procion dye on a stretch poplin, squirting it on and then using a paintbrush to soften where the colours blended.
I have another one cut, this time a plain + print combo, then I am going to make Jalisa a halterneck dress with flared skirt.