I soaked the rovings overnight and then applied the dye in a rainbow-ish pattern. After they dyeing, I rolled them in cellophane and let them sit for a few days. Overnight is probably enough, but things got busy with work so the steaming part was on hold.
I steamed them for a total of 45 minutes. Flipping them every ten minutes. After four flips, I turned the heat off and let them cool down in the steamer. About three hours after that, I unrolled them and let them cool even further.
Here's what they looked like after I rinsed all the dye out of them.
I wish I had made one of these for me, so I could see what the spun yarn looked like. Next time. . . . . better planning.