Q.Orange Color in Orange Tree
I need the color of my oranges to change from green to orange upon the orange ripening. I prefer the color change from orange green to a strict orange color upon ripening. The farm is 100 Kilometers from the city of Nairobi in Kenya; therefore, just around the equator at an altitude of 5,000 feet above the sea level.
Thank you,
Muthoka J Mutungi

This link will help you.
https://www.gardeningknowhow.com/edible/fruits/oranges/harvesting-oranges.htm