Homemade concrete dye involves some type of pigment, either liquid or powdered, being added to the actual concrete mixture. Concrete is mixed with water and therefore, any concrete dye must also be water soluble. Oil-based colours will not work to dye concrete, so care must be taken when choosing and mixing the correct pigments together. This will be a trial and error procedure that will only achieve the desired results depending upon the amount of the dye that is added.
Add a latex paint or any water-soluble paint to a concrete mix. Use the paint like water in the same proportion when adding it to the concrete. Additionally, any type of powdered paint pigment can be mixed with water in a bucket and added to the concrete. Always maintain the proper proportion of dyed water to the concrete manufacturers recommended mixing directions.
Add clothes dye to a bucket of warm water and stir. Mix it in proportionately with the concrete. The lime in the concrete is the fixative here, no need to add either salt or vinegar. Start with one teaspoon of dye to one quart of water, but this is variable and depends completely on how dark or light you want the colour to be. As an example, for 1 square foot of blue concrete, add a full teaspoon of dye to the required water. This will create a dark blue. Add half of a teaspoon to the water for a lighter colour blue. Adjust the dye colour in this way to achieve the concrete colour that you desire.
Add food colouring in the same way as a clothes dye pigment. Food colouring is not as concentrated as clothes dye, so it is best used for smaller projects. Food colouring can be added straight into the concrete without mixing it into water first.
Mix and match dyes and pigments to make the perfect coloured homemade concrete dye. This will be very much a trial and error project, and only you can decide how much dye to add for vibrance, colour intensity and whether the colour will be a darker or a lighter shade.
Always wear rubber gloves when working with concrete and dyes.