The present invention relates generally to the field of colouring compositions. One aspect of the invention is a colouring composition having a blue colour. In particular, the present invention relates to a colouring composition having a blue colour wherein the composition comprises anthocyanins, metal ions, and at least one stabilizer. The metal ions are selected from Al(III), Ca(II), Cu(II), Fe(II), Fe(III), Mg(II), Mn(II), Zn(II) and combinations thereof while the stabilizers are selected from tannic acid and phospholipids. The invention provides for example a composition comprising the colouring composition and also provides for the use of the colouring composition to colour a food, a nutritional formulation, a food supplement, a beverage, an ink or a pharmaceutical product. A further aspect of the invention is a method of preparing a blue colouring composition.