Combine rice flour, tapioca flour, green pea flour, thick coconut milk and water together.
Add yam paste to mix and stir in alkaline water. Strain the batter to remove lumps. Mix sugar, water, salt, thin coconut milk and screwpine leaves in a saucepan. Bring to a simmering boil until sugar dissolves.
Strain the syrup into the batter. Discard the screwpine leaves.
Divide batter into 3 equal portions. To one portion add a little purple colouring. To the second portion add a little pink colouring and leave the last portion plain.
Lightly grease a 20cm square cake pan and place it in a steamer. Steam for 4-5 minutes.
Steam each individual layer of batter alternately for 4-5 minutes over rapidly boiling water. The remaining batter would be the final layer. When all the layers have been completed, steam for 15-20 minutes.
Brush the layered kuih lightly with corn oil and leave to cool completely for 5-6 hours before slicing into bite-sized pieces.