Colourants are classified into dyes and pigments, the difference between dyes and pigments dependent on physical characteristics rather than the chemical composition which meanmeans both have similarity in general chemical structure but have different solubility in the application medium, where dyes are usually water soluble . On the other hand, pigments are insoluble in water and most of the other solvents and can be achieved by avoiding solubilizing groups in the molecule or by forming insoluble organic structures.