Garbage sorting as an Olympic sport

I always heard that Europe was more ecologically aware than we are in the US, but never imagined to what extent.  We have now decided that they should add German garbage sorting as a new, exposition/demonstration sport in the summer 2012 London Olympics.  We are required to sort our trash into 4 categories.  There are separate, color coded garbage cans for each.  You are on your own to come up with a system for in your kitchen.  Newer kitchens actually have trash ares that have 4 designated areas.  Yellow is for plastic and metal.  This would include cans and plastic bottles, but also ziploc bags, envelopes that have a plastic window or "coated" paper. Blue is for paper-easy, also includes cardboard.  Brown is for "bio". This is essentially anything that my Aunt Riki would compost; tea bags, egg shells, raw foods like the brown ends you cut off of celery.  Last is black or grey.  This is for "other household trash".  Seems straight forward, right?  So here are our dilemma items:  Where do you put a used tissue?  Paper, bio or household?  Where to you put cooked fish bones or mussel shells?  We went with bio on the fish bones-wrong, they go in household...see what I mean?  You could create all kinds of sorting challenges!!!  I am sure my brother, Greg is loving it!  I also suspect that he is secretly jealous that he only has two categories of sorting in his little village...