The present invention relates to a food grade colouring agent for the preparation of coloured ice cubes, wherein the colouring agent comprises dried red cabbage, to a method for the preparation of the colouring agent, comprising the steps of chopping and drying red cabbage, to a method for the preparation of a coloured liquid, wherein the colouring agent is extracted with water and/or ethanol, and to the use of the coloured liquid for the preparation for coloured ice cubes or confectionary.