Line an 8-inch square baking pan with parchment paper overlapping the sides (for easy lifting).
In a heavy bottomed 3-quart saucepan over medium heat, mix the sugar and the water over medium heat. Cook until the mixture reaches the soft ball consistency, or a temperature of 235 degrees F on a candy thermometer. Stir in the coconut, cardamom and add food coloring, if using. (The toffee should be a pale, gentle pink.)
Quickly spread the mixture evenly into the prepared pan, firmly pressing it into the corners. Allow it to cool and harden (takes a number of hours!). Cut or break into delicate squares or pieces and enjoy!