IC storage using conductive cases?
1) The black foam is conductive and safe to store ICs.

2) The pink foam is not conductive but prevents charge buildup. I would not use this for storing ICs.

3) You do not need a Faraday cage to store ICs. OK, unless you store them in an environment where there are strong magnetic and or electric fields present. That almost never happens. You should not store ICs in such environments anyway.

4) As a hobbyist don't be too fussed about storing your ICs, most ICs which hobbyists use aren't even that sensitive anyway. I am very aware of how ESD works (I design ICs for a living) yet I have been storing the ICs I use for hobbying in a simple plastic drawer which is very much non-ESD safe. And I never had a problem with those ICs.

5) In a pinch you can use any foam you like and wrap some aluminium foil around it and stick your ICs in that !