In the electrolytic colouring of aluminium, also known as the Colinal process, the anodised aluminium is coloured in a metal salt solution under alternating current. Varying the duration of treatment produces various shades of beige-brown to black. This light- and weather-resistant process offers similar application properties to colourless anodised aluminium.
With chemical colouring in the dipping process, black, the anodised aluminium is given a deep black surface by organic and inorganic colour solutions.
Colour anodising offers a wide range of design options for aluminium by not only strengthening the metal but by enriching it with a variety of colours.