Green Mountain Diapers does not endorse the dying of their prefold diapers.
I emailed them to see if I could include a link to their site for sizing purposes and was asked not to because they do not endorse dying of prefolds.
I will be researching more the effects of dyed diapers but after my first stocking on Hyena Cart...all GMD prefolds will be sold undyed. I dyed quite a few last night so what I stock (most likely on June 17th) will be IT for dyed GMD's.
I am looking into other vendors to satisfy the dyed prefold niche as I love dyed prefolds and plan to continue offering them. I will continue to dye my boys diapers until I find evidence that shows me that it is in-fact harmful.