They are filled with bags of plasma that should be yellow but isn’t always. My plasma, probably, is green. I’m female and menopausal and taking hormone replacement therapy, and all those factors—along with the contraceptive pill—turn women’s plasma green. Off and odd-looking. They don’t know why, and it doesn’t really matter, as all female plasma is discarded anyway, since NHSBT introduced a policy of “male donor preference” in 2003.
