Peel the tangelos and using a very sharp knife, slice them (at right angles to the segments) into slices about 4mm. thick. Transfer the slices to a pretty bowl and arrange them so that each slice overlaps the slice before. To make the caramel, heat the brown and white sugars together with the water and bring to the boil, stirring to dissolve the sugar and brushing the sides of the saucepan down with cold water occasionally. As soon as the mixture begins to boil, stop stirring and allow the mixture to boil until it turns a deep caramel colour, approx. 5 minutes. Immediately remove from the heat and allow the bubbles to subside. Carefully pour in the orange juice, taking care as the mixture can sizzle and spit. Mix the orange juice in well, returning to the heat if necessary to help the mixture combine. Pour the caramel over the tangelos, making sure that all are covered. Cover with plastic wrap and chill for up to 24 hours but for at least 8 hours. Serve with fresh cream if desired. Per serving: 843 Calories (kcal); 1g Total Fat; (1% calories from fat); 11g Protein; 213g Carbohydrate; 0mg Cholesterol; 32mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 0 Vegetable; 8 1/2 Fruit; 0 Fat; 4 1/2 Other Carbohydrates Converted by MM_Buster v2.0n.