I believe these are a Pholiota species, with a pleasant orange on top and a dark brown underneath. Many species of fungi serve well as dye, and Phaeolus schweinitzii is even know colloquially as the “Dyer’s polypore”. It’s good to note here, that aside from a few anecdotal reports of contact dermatitis from some species, as a general rule it is safe to handle any mushroom without gloves, even deadly species.
Hapalopilus croceus here, showing a nice dark orange.
The mushrooms are chopped into large chunks, then added to a cast iron Dutch oven. The mushrooms are covered with water and boiled for 30-60 minutes, occasionally pressing with a mallet.
The mushrooms are strained from the dye bath with cheesecloth.
A wool cap before dyeing.
Soak the wool in lukewarm water for half an hour, then add the wool to the dye bath and return to heat, using a mallet to press bubbles out.
Bring to a very low simmer, and gently move the wool in the dye bath, being careful not to agitate it much and warp the wool.
After removing, rinsing, and dyeing, the cap has taken on a slightly darker, olive green tint. I’d prefer a darker shade and continued experimenting with different mushroom species and various mordants added to the dye bath.
Another attempt with an identical cap, using Ganoderma applanatum with half a cup ammonia added to the dye bath fifteen minutes after immersing the wool, and 2 tsp alum with 5 tsp cream of tartar added after 45 minutes.