The rainbow apple logo was a tribute to Alan Turing, an English mathematician and computer scientist, whose concepts played a considerable part in the development of the modern computer system. Turing was homosexual and was heavily persecuted , at the time, illegal in the UK. In 1954 he committed suicide, by cyanide poising. A half eaten apple was found with his body, which was thought to have contained the cyanide. Hence forth a half eaten apple was a symbol for Alan Turing and his life’s work; and thus the apple logo, with a bite out of it was a reference to this. and the rainbow stripes could also relate to this, being a gay symbol.