1.Grease a deep 19cm square cake pan; line base and sides with baking paper.
2.Stir sugar, milk and glucose in a medium saucepan, over low heat, until sugar dissolves. Bring to the boil; boil, uncovered, for 5 minutes or until mixture reaches 112°C on a sugar thermometer (or until a small amount of mixture, dropped into cold water, forms a soft ball when rolled between your fingers).
3.Remove pan from heat; pour mixture into a heatproof bowl. Stir in coconut until thick and creamy. Spoon half the mixture into another heatproof bowl; work in colouring. Press pink mixture firmly over base of cake pan. Press white mixture evenly over pink layer.
4.Refrigerate for 3 hours or until firm before cutting into squares.
Coconut ice can be made a week ahead; store in an airtight container in the refrigerator.