Here is a quick description of a successful experiment using madrone:
https://jenjoycedesign.com/2020/07/25/a-natural-dye-experiment-part-2/
Thinks to note:
The dye materials must be heated to extract color. A week-long soak in the sun is one way to get things started, but jus5busung the stove is fine. Don’t boil! A gentle simmer. Typically for at least an hour, though I unusually go longer.
Once it’sremoved from heat, let it sit for awhile, at least overnight. You will get stronger color the longer it soaks.
Soak your clean wool thoroughly (minimum 1/2 hour) before adding it to the cooled dye pot (after the dye material has been strained out). Don’t add room temperature wool to a hot dye pot - you risk felting/fulling* the wool.
Wool deteriorates in high ph. Most wool dyeing involves adding vinegar (the kind in kitchen cupboards) or citric acid crystals
Kool-aid makes a great fuss free dye for wool because it already contains citric acid.
Wool will also deteriorate if your dye pot is too hot. Heat is good, up to a limit. Heat the pot slowly, and try not to let it get above a slow simmer. If it boils you will still get dyed wool, but it will most likely lose softness, become a little crunchy, and wear out faster.
Simmer for an hour or so, then let it cool before removing the fiber. In fact, for many natural dyes, the longer you leave the fiber in the dye water, the more dye that gets taken up.
There is great variation in color- and light-fastness when dyeing with natural dyes, depending on the plants used. It helps to wash natural dyed items gently in cool water, and hang to dry away from sunlight.