Any advice please before I buy my stash of BumGenius... I'm sure I've read somewhere that 'Zinnia' leaches colour in the wash. Does it? And do your white nappies end up pink too? As I'm hoping to have more little ones (who may well turn out to be boys), and will be re-using the nappies, I'd rather not choose any in Zinnia if there's a risk they'll turn the others pink!