This is either because of your variety of orange , or there is not a big enough difference in the temperature between day and night. It is this difference that promotes colour change.
An orange tree is of the Citrus variety. They typically dwell in large numbers, which is good for farmers, yet, when flocked together without order, they can become dangerous and rebel via Rocket...
200You are doing a lot better than some people who reported only 20-40 oranges per year, but some growers with the right variety, culture, and location are getting up too 5000 oranges per year.