a friend of me has had the same problem; after a few days (5-7) of perfectly white mycelium and shrooms growing blue spots appeared; they slowly spread all over the cake; but they were not powerderlike or slimy (the spots i mean) and didn't smell odd even after about 5-8 days; also his older shrooms (not mature then) stopped to grow, but at the same time new shrooms appeared all over the cake;
the blue on the mycelium could be rubbed away; it wasn't really sticked to the cake;
the shrooms do not look infected at all; so he is a bit unsure if he can use them or not;
any suggestions?
thx a lot
laxxax