Green Tomato - UPDATE

Thanks to the good frost this morning, my tomatoes, zucchuini and squash are all black... and the squash had just started to flower - being self seeded I was letting nature take its course. Nature can be a fickle friend at times.

Now where did I leave my rotary hoe? That's right I don't have one, well out with the garden fork and spade this weekend it is. I love the smell of freshly tilled soil early in the morning.

Green Tomatoes

Why do they not go RED? I realise there has been a change of government and I hardly expect them to go BLUE but there they are sitting on the plant, as green as the leaves and no sign of changing.

Thoughts/hints/ideas?