It's a speckled wood, but it's the Southern one, they say the Rhone (I think) is the river that divides the orangy one from the creamy one (that we get). But Peter will know the details!!!!
I saw an Orangy one in Hampshire a couple of years ago.
If the wings had dark borders then they could have been one of the clouded yellow variants, pale or berger's, otherwise brimstone or perhaps cleopatra's brimstone.