Hi Wayne, The colours are awesome aren't they!?
Read this somewhere, if I remember where I'll post the link!
It's basically the leaves' natural sunblock, optical filters called anthocyanins, they're produced when leaves receive more light energy than can be used in photochemistry & photosynthesis begins to fail, photoinhibition, which in a severe case could cause reactive oxygen which would in turn damage the plant causing DNA damage etc & the anthocyanins produced reduce the damage caused by this & help aid recovery.
Hope I got that right-no doubt someone will help out if not!?
Wish I had the something along the lines of a natural sunblock, when I go red it's too late & it's aloe vera time, gotta love those plants!
Will