About indigo
Indigo-dyed fibres may bleed or stain your hands and needles while knitting.
This is completely normal as some of the indigo molecules are released by friction (you have a clear example with the jeans). Once you wash your hands, the blue stains disappear.
When mixing colours with indigo, these loose molecules do not usually bleed, although, as always and especially when working with very saturated colours, we recommend knitting and washing a small swatch.
All the blue colours you find in the shop are dyed with indigo, as well as some others that we over-dye in other colours to broaden the palette. For example, we obtain some greens by giving yellows an indigo bath.