The Daily Mail account can be read here
Other factors may also be involved. Judith Hooper's book 'Of Moths and Men' provided some interesting discussion about environmental factors that may change the moths colouration during the caterpillar stage.
‘Induction over the history of science suggests that the best theories we have today will prove more or less untrue at the latest by tomorrow afternoon.’ Fodor, J. ‘Why Pigs don’t have wings,’ London Review of Books, 18th Oct 2007