Quick answer
How is concrete colored?
Five methods, used alone or together. Integral pigment is batched through the whole mix. Color hardener is a dry pigment floated into the fresh surface. Acid stain reacts chemically with the cured concrete to form a permanent mineral color. Water-based stains and dyes deposit pigment into the surface pores. Tinted sealers add color in the coating itself. Only integral pigment and acid stain are genuinely permanent.
- Most permanent
- Integral + acid stain
- Most color range
- Water-based stain & dye
- Works on old slabs
- Stains, dyes, tinted sealer
- Most natural variation
- Acid stain
"Stained concrete" gets used as a catch-all for half a dozen genuinely different processes with different chemistry, different permanence, and different results. Knowing which one is being proposed matters, because a quote for "staining" could mean a permanent chemical reaction with the slab or a colored sealer that wears off in five years.
The most useful distinction is where the color lives: through the concrete, chemically bonded into the surface, sitting in the surface pores, or in a film on top. That ordering also happens to be the durability ordering.
The five coloring methods
In order from deepest to shallowest — which is also roughly most to least permanent.
- Integral pigment
- Color added to the whole batch at the ready-mix plant, so the concrete is colored all the way through. Won't wear off or fade meaningfully, and a chip reveals a similar tone rather than gray. Limited to earthy, muted tones, and the color is set before the truck leaves the plant.
- Color hardener
- A dry pigmented powder broadcast onto fresh concrete and floated into the surface. Produces richer, more saturated color than integral pigment and simultaneously densifies the top layer. Sits in the top few millimeters, so deep abrasion can eventually reach through it. The standard for stamped work, usually over an integral base.
- Acid stain
- A solution of metallic salts in a mild acid that reacts chemically with the free lime in cured concrete, forming a new mineral compound in the surface. Genuinely permanent — it cannot peel or wash out. Produces mottled, translucent, unpredictable color. Limited to earth tones: browns, tans, terracottas, blue-greens, and near-blacks.
- Water-based stain and dye
- Fine pigment or dye carried into the surface pores. No chemical reaction, so results are more uniform and predictable, and the color range is enormous — including blues, reds, and greens that acid stain can't produce. Dyes in particular are vivid but generally less UV-stable, which is why they're mostly used indoors.
- Tinted sealer
- Pigment carried in the sealer itself, forming a colored film on the surface. The cheapest and least permanent method — it wears where traffic is heaviest and has to be reapplied to maintain appearance. Useful for refreshing tired decorative work, and a poor choice as a primary color method.
Why acid stain looks the way it does
Acid stain is worth understanding on its own because it behaves unlike any other coloring product, and that behavior is either exactly what you want or exactly what you don't.
It doesn't apply color — it causes a chemical reaction. Metallic salts in a mildly acidic carrier react with calcium hydroxide in the cured concrete to form insoluble colored compounds within the surface. The color is literally part of the concrete afterward, which is why it can't peel, flake, or wash away.
Because it's a reaction with the concrete, the result depends on the concrete: how it was finished, how it cured, where the paste is richer or leaner, where a trowel passed twice. Two slabs from the same truck stained with the same product on the same day will come out differently. Within a single slab, the color varies continuously.
That's the whole appeal. Acid-stained concrete has a depth and organic variation that looks like weathered stone or aged leather, and it cannot be replicated by a uniform coating. It's also why anyone who wants a single consistent color across a large floor should be steered toward a water-based product instead.
How a staining job actually runs
The process for acid staining an existing slab. Water-based staining follows a similar sequence without the neutralising step.
Assess and test
Check the slab for coatings, sealers, curing compounds, and contamination. Any of these block the reaction. A test patch in an inconspicuous area confirms both that the concrete will take stain and what color it will actually produce.
Prepare the surface
Strip existing sealer or coatings, degrease, and clean thoroughly. On dense or previously sealed slabs this often means mechanical grinding to open the surface. Preparation is most of the job.
Mask and protect
Acid stain will react with anything containing lime and will damage metal, plants, and finishes. Adjacent surfaces get masked properly.
Apply the stain
Sprayed on with an acid-resistant sprayer, often worked with brushes or sponges to control mottling. Multiple colors are commonly layered for depth.
Let it react
Several hours, sometimes overnight. The color develops progressively and looks nothing like the final result while wet.
Neutralise and rinse
The residual acid must be neutralised — usually with a baking soda or ammonia solution — and all residue removed. Sealing over unneutralised residue causes adhesion failure, and this step is the one most often rushed.
Dry, then seal
The slab must be fully dry before sealing. Then two thin coats of sealer, with a grit additive outdoors or wherever slip matters.
Choosing a method
| If you want… | Use | Why |
|---|---|---|
| Color on an existing slab, organic and variegated | Acid stain | Permanent, translucent, and the most natural-looking result available. |
| Color on an existing slab, uniform and specific | Water-based stain | Predictable, huge color range, no acid handling or neutralising. |
| Bright or unusual colors indoors | Dye | Vivid and saturated. Limited UV stability makes it an interior product. |
| Color that survives chips and deep wear | Integral pigment | Goes all the way through. Must be decided before the pour. |
| Rich color on new decorative work | Color hardener over integral | Depth and surface durability together. The standard on stamped work. |
| A refresh of faded decorative concrete | Accent stain plus new sealer | Restores depth for a fraction of resurfacing cost. |
Indoor and outdoor differences
Interior floors are the ideal application. No UV, no freeze-thaw, no rain, and the sealer lasts far longer — often eight to ten years rather than two or three. Dyes and vivid colors are viable indoors precisely because there's no sunlight to fade them. Polished and stained concrete floors are among the most durable and lowest-maintenance floors available.
Outdoors, three things change. UV exposure limits which products make sense — acid stain and integral color hold up, dyes generally don't. Sealers wear far faster and need renewing every two to three years. And slip resistance becomes a live safety question, which means a matte sealer with a grit additive rather than the gloss finish that looks so good on an interior floor.
Concrete coloring questions
Related reading
Key takeaways
- Five methods: integral pigment, color hardener, acid stain, water-based stain or dye, and tinted sealer.
- Acid stain is a permanent chemical reaction with the concrete — it can't peel or wash out.
- Because it reacts with the slab, acid stain reveals every patch, repair, and curing variation. Test first.
- Water-based stains give predictable, uniform color and a far wider palette.
- Neutralising after acid staining is non-negotiable. Sealing over residue guarantees failure.
- Interior stained floors need resealing every 8–10 years; exterior every 2–3.
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