To be on the safe side I thought I would knit a swatch with some of the natural dyeing I have been doing. I included yarn dyed with red cabbage and also yarn from the Mexican blossom bush.
I thought I should put it through the wash to test wash fastness. I totally expected fading.
I didn’t expect a complete colour change. The lilac colour in the skein turned a cruddy blue colour. Truly amazing. Whereas the green from the Mexican blossom bush was unchanged.