Sal, More time on the tree to develop during cooler temperatures makes a lot of sense. I've had Kadota make the same color change from amber to deep red as the season progressed - and I chalked it up just to dropping temperatures.
Last summer was cooler than usual, and everything slowed down. Most figs were at least three weeks later than normal. I got this Conadria breba at the beginning of August. If just temperature were causing color change, I don't think it could have gotten this dark by August 1st. I think you are right - the longer time on the tree allows more development.
