Hi. Just saw your message (just back from vacation) I think I know the dye you asked about. I'm pretty sure it was an experiment with acetone and dish soap with red and black powder dye on a yellow ace race disc.
Best I can tell you is experiment and have fun with it. My basic dye for spinning is a dash of powder rit or idye poly with about a capfull of acetone and then add detergent to thicken. The thicker the mix (and you can add powder to make it more vibrant) the less it moves so it is nice for painting solid areas at low speed. A thin acetone mix will more easily 'spin out'... especially at higher speeds. I like to just play around with thick and thin mixes of at least 2 colors at varying speeds and just let the magic happen. Hope this helps
Best I can tell you is experiment and have fun with it. My basic dye for spinning is a dash of powder rit or idye poly with about a capfull of acetone and then add detergent to thicken. The thicker the mix (and you can add powder to make it more vibrant) the less it moves so it is nice for painting solid areas at low speed. A thin acetone mix will more easily 'spin out'... especially at higher speeds. I like to just play around with thick and thin mixes of at least 2 colors at varying speeds and just let the magic happen. Hope this helps