Indigo deserves a special mention, as it is a singular dye within natural dyeing.
As with other blue-dyed garments, indigo-dyed fibres may release a small amount of colour during knitting: some of its molecules are loosened by friction and may temporarily stain hands or needles. This behaviour is normal and disappears when hands are washed.
When indigo is combined with other colours, these loose molecules do not usually transfer. Even so, and especially when working with highly saturated shades, we always recommend knitting and washing a small swatch.
All blue shades available in the shop are dyed with indigo, as well as some additional colours obtained through overdyeing to expand the colour palette; for example, certain greens are created from a yellow base over which an indigo bath is applied.