Hi,
It is rather surprising to learn that a vulcanized tyre such as Vittotira's (with the SC being an exception) responds so well to aging.
The only reason for this I can think of is that the vulcanisation process is stopped before it is completed at the factory. It then continues during storage by binding sulphur molecules available in the surrounding air.
What strikes me though is that ever since the advent of the new 320 tpi tyres Vittoria somehow lost it's book of compound recipes. Those compounds seem to be allover the place and none actually as good as the one they used for the older 290 tpi tyres. Not that it was that great to begin with but still....
BTW, don't judge a tyre by its colour. Pigmentation never did any good to rubber, never will....
Ciao,

Being a snob is an expensive hobby.