Definitely worth a try

First time I've seen these in the market, they called them 'Chocolate Oranges' from Spain $9.99/ 3.6 kg Box @officialfarmboy

Chocolate Oranges have a greenish brown skin on the outside, but are not chocolate on the inside. They have a very lovely sweetness than regular Navel Oranges, have a lower acidity and are juicier, with no hint of sourness. Plus with such a lightly thin skin that is still fairly easy to peel. They are perfect enjoying oranges due to their strong zesty fragrance and seedless flesh.

Navel Chocolate Oranges are available for a short season in winter. Definitely worth a try if you get the chance.