Combine rice flour, tapioca flour, green bean flour, water and thick coconut milk in a mixing bowl. Strain the batter to remove any lumps. Add colouring to mixture.
Put sugar, salt, water and screwpine leaves in a saucepan. Bring to a boil and heat until sugar dissolves. Strain the syrup into the batter to mix. Add 2 tablespoons of cooked red beans to the batter. Cook the batter over low heat for 1 minute.
Red Bean Layer: Pressure-cook the red beans until soft. Drain the beans and set aside.
Combine rice flour, tapioca flour, water and thick coconut milk in a mixing bowl.
Put sugar, salt, water and screwpine leaves in a saucepan. Bring to a simmering boil and heat ingredients until sugar dissolves. Strain the syrup into the batter. Add remaining beans to mix. Cook the batter over a low heat for 1-2 minutes.
Lightly grease a 22cm square cake tin. Warm the tin in the steamer for 1-2 minutes. Pour in two-thirds of the pink batter and steam over medium-high heat for 8-10 minutes. After the batter has set, add the red bean batter.
Steam for 10-15 minutes. Add remaining pink batter and continue to steam for 30-40 minutes over medium-low heat until the kuih is firm. Remove and leave to cool completely before cutting into slices.