In a saucepan combine all the ingredients for the white layer then bring to a boil over medium high heat, stirring. Fill a glass with cold water and set in near the stove. Keep stirring the coconut ice while it boils, keeping an eye that it does not burn or boil over. Drop a small amount of hot mixture into the cold water until it forms a soft ball in the water. When it has reached soft ball stage, remove from heat and transfer to a large bowl. Whip in the bowl with mixer until it begins to thicken and looks creamy. Pour into the greased cake tin. Set in the fridge to cool.
In the same saucepan, combine the ingredients for the pink layer, excluding the food colouring. Bring to a boil over medium heat, stirring until reached soft ball stage. Stir in the food colouring until the desired colour is reached. Pour into the bowl and whip until mixture begins to thicken. Pour over the white layer and smooth down with a spatula. Refrigerate until sit then slice into squares.