It was a very large mess. I hate to say it was *huge* mess, but that's only because we did this particular project outside. With a tablecloth on the picnic table.
And yet, still, it's three days later and I am still scrubbing dye off my hands.
(And I wore gloves. You might be thinking, huh, I'm pretty sure you've done enough of these craft projects to know never use the gloves that come with the package because they are cheap and flimsy, but in this case, you'd be wrong.)
The other part of this that I might have done differently: I would have dyed the rainbow in the opposite direction, and had the purple paint up near the toes of the sneakers - but that's totally a personal preference. The 7 year old has way more purple clothing than red, so she would have liked if they had been more matchy-matchy with her clothes, but tie-dyed rainbow sneakers are super cool anyway you look at it.
We may even have to add a few sequins to the sneakers just because.