Iron oxide pigments can be used to colour concrete, mortar and renders providing a coloured surface that eliminates the need for painting or other coatings. Instructions STEP 1 Prepare a test panel before carrying out your project to ensure that the colour meets your expectation. STEP 2 Accurately measure oxides to ensure that there is no colour variation between batches. STEP 3 Pre-mix the oxide with aggregate for 15 seconds before adding cement. After adding the cement mix for a further 20 seconds before adding water. Available sizes