Pale Tussock Dark Colour Form

Stars of the catch for 19 May 2014.
This color form of the Pale Tussock was also seen a lot around Sussex this year.
Would be interesting to know if the caterpillars or pupae of this form are darker as well or if the wet weather helped this color survive better this wet winter, with no snow and wetter darker trees, they over winter as a pupa, but you never know.