Peel and seed lychees and leave aside in a small bowl. Combine sugar, agar-agar powder and water in a saucepan and bring to a boil. Reduce the heat and simmer for 3-5 minutes.
Spoon a ladleful of agar-agar solution into the lychees in the bowl and leave to soak for less than a minute. In the meantime, pour a ladle of agar-agar mixture into the ring mould. Then pick up the soaked lychees and arrange them around the ring mould. Top up with a layer of agar-agar mixture and leave to set.
Divide remaining agar-agar mixture into 2 equal portions. Add yellow colouring and fresh milk to one portion and stir in shredded dragon fruit, and pink colouring to the other portion.
Use a fork to lightly scratch the lychee portion. Pour in the yellow portion of the agar-agar mixture. Leave aside for a while.
Once the yellow porion is set, scratch the layer lightly with a fork, then pour in the dragon fruit layer. Leave aside to set completely then chill in refrigerator for about 2-3 hours before removing the jelly from the mould.