biochemistry - What are the variables that control/influence the color of oranges(Citrus sinensis)?

I hear that Oranges cultivated in tropical areas of the world tend to be greener when ripe, is that correct?
Even the same type of Orange differs in color if cultivated in California or Florida. I hear that's because of the climate (colder nights == oranger oranges)

But, at the same time, oranges tucked in between the tree leaves tend to be greener, for they need more chlorophyll to make the most use of less access to sun rays.

Could someone correct my assumptions? Also, if possible, list the pigments and processes involved?