At BECOSAN we do not alter the colour, and the final colour of the paving will be the colour of the paving itself. There are two ways of colouring or tinting concrete, superficially at the time of trowelling by applying a powdered colourant to the wearing course or by colouring the mass concrete. These two techniques are only possible with fresh concrete. For existing pavements, there are techniques for applying liquid and acid dyes, but the results are generally not very promising. For more information