Everbuild opti mix cement colourant everbuild optitonebk1 opti mix cement colourant s a one shot cement colourant that enables accurate colour matching and consistency between different batches of mortar it has a fast colouring formulation a controlled dosage a consistent mix design and is easy to use and less messy than powder it produces no waste and no more colour differences in mortar batches 1 litre is equivalent to 5 litres of standard product everbuild optitonebk1 opti mix cement