You know when you boil carrots the water turns slightly orange? If you leave the water to go cold it turns green 
Why is that? 
I only parboiled the carrots pre-roasty style 
Carrots have been "bred" over the years to be orange. It is claimed that the Dutch bred them from Wild Carrots, which vary in colour from white to red and are very bitter in taste, to produce a vegetable in their (Dutch) national colour. Carrots often revert to green if, whilst growing, they are exposed to daylight (if for example the tops grow above ground).
"Unripe" carrots frequently have a green centre.
