The purple-red or violet phycochromaceze contain phycochrome, which is composed of chlorophyll and a purple, but generally (not apparently different) blue modification of phycocyan, which easily turns into a verdigris-coloured substance.

Then the dirty-handed society went off the wash, followed by the Professor, trying to calm the anxiety of Rob, who had been told by Tommy that all water was full of invisible pollywogs.

"When I found the letters with a name which matched the initials I felt very Sherlock Holmesish. […]

Another common error dealing with memory is that of hindsight bias. This is the tendency to exaggerate what could have been anticipated in the past. This is also known as Monday morning quarter backing or hindsight is 20/20 where the right decision as to what should have been done appears to be more obvious now than it was in the past. Facing Reality: An Introduction to Philosophy Revised Edition, PhD Joseph Grcic