Place the glutinous rice flour in a mixing bowl and slowly add water until a dough forms and starts to pull away from the sides of the bowl and no longer sticks to your fingers. You may not need all the water to reach the proper consistency. Knead the dough for another 5 minutes.
Divide the dough into half. Add as much food coloring as you'd like to one half to make it pink or red. Knead the dough until it is evenly colored.
Pinch off pieces of the dough and roll into marble-sized balls between the palms of your hands.
Heat a large pot of water and bring to a boil. Prepare a bowl of cold water to cool the cooked dumplings. Drop the balls into the boiling water one by one but do not overcrowd the pot. When the dumplings float to the surface, let them cook for 1 minute more.
While the dumplings are cooking, place 1 litre of water in another pot together with the ginger, sugar and tangerine peel. Bring to a boil and cook until the brown sugar has melted. Reduce the heat to medium-low and simmer until the syrup is aromatic, about 30 minutes.
To serve, place a few dumplings in a small bowl and pour some syrup over. Serve hot.
You can also stuff the dumplings with a ready-made paste made with peanuts, black sesame seeds or red beans.
Add pandan leaves to the syrup instead of tangerine peel or ginger.