This may be one of the more strange requests that is really and truly whistle-related.
I’ve made a bunch of whistles according to instructions on the Low-Tech whistle web-site. And worked out how to make a Low D (and a Low G).
But all these whistles are made from barrier-pipe PVC. It’s unrelenting white.
In my experience there isn’t anything that would colour PVC that would not wear away quickly under the abrasion of normal play.
Tell me I’m wrong. Is there anything I can use to paint or stain a white PVC whistle? If I could have one that looked like a tie-dyed tee-shirt I would be delighted.