How to Mix Coloured Concrete with Iron Oxide

Iron oxide is the pigment that gives concrete its colour — the same family of pigments used in commercial pavers and decorative concrete. A small amount mixed in the right way produces a rich, even shade that runs right through the piece and does not fade or wash off. Here is the whole process in under a minute:

The method, step by step

1. Measure your ingredients. Measure out the cement mix, colour oxide pigment, and water according to your recipe. Getting the pigment amount consistent from batch to batch is what keeps your colour repeatable.
2. Combine the dry ingredients. Add the colour oxide to the dry cement base and mix thoroughly, so the pigment is evenly distributed before any water goes in. Mixing dry first is the key to even colour with no streaks.
3. Add water and mix well. Pour in the water and stir thoroughly, scraping down to the bottom of the container so nothing is left unmixed. You can hand-mix or use a drill blender for a more thorough blend.
4. Adjust the consistency. If needed, add a small amount of extra water to reach a smoother, more fluid consistency before you pour or shape your piece.

A little pigment goes a long way, so start conservative and increase gradually — you can always add more next batch, but you cannot take it out. And because the colour is mixed all the way through, keep your pigment amount consistent between batches if you want pieces to match.

The quality of the pigment matters: true iron oxide gives clean, lasting colour that holds up outdoors, while cheaper colourants can fade. For more on choosing and using pigments, see our complete guide to iron oxide pigments for concrete.