Contents
A shampoo carrying direct dyes, so that washing tops the colour up instead of stripping it. It is a slightly contradictory product — surfactants remove pigment while the dyes add it — and understanding that tension explains both why it works and why it works less well than a Colour-Depositing Conditioner.
The tension in the format
Washing is what fades hair colour. Anionic surfactants lift the cuticle slightly, and water carries dye molecules out. A colour-depositing shampoo puts pigment back during the same operation, so the net result is roughly stable rather than steadily declining.
Two consequences follow:
- The deposit is modest. Contact time is short, and the surfactant is working against the dye. This is a maintenance product, not a colouring one.
- Conditioner formats deposit more, because there is no surfactant fighting them and the cationic base is attracted to the hair rather than stripping it. Where both exist, the conditioner is the stronger tool.
What is in it
| Class | Doing what | Names |
|---|---|---|
| Surfactant | Cleans | Sodium laureth sulfate, cocamidopropyl betaine, coco-glucoside |
| Direct dye | Deposits colour | Basic Brown 17, Basic Red 51, HC Blue 2, Acid Violet 43 |
| Cationic polymer | Helps dye adhere despite the surfactant | Polyquaternium-10, guar hydroxypropyltrimonium chloride |
| Conditioning agents | Offset the strip | Silicones, fatty alcohols, panthenol |
| Preservative | Essential | Sodium benzoate, phenoxyethanol |
Sulfate-free versions deposit better, because a milder surfactant removes less of what is being added.
Using it
- Gloves. Vivid pigments stain hands and nails badly.
- Leave it on. The instruction to let it sit for three to five minutes is where the deposit actually happens; a thirty-second wash deposits almost nothing.
- Alternate with a plain shampoo. Daily use of a depositing shampoo builds pigment on porous ends, and the ends go progressively darker or more saturated than the roots.
- Cool water.
- Rinse the shower immediately — these stain grout, silicone and enamel.
The purple shampoo confusion
The most-sold product in this category is purple shampoo, and it is a toning product rather than a colour-depositing one in the usual sense: the violet pigment is there to neutralise yellow on blonde hair, not to add violet as a colour. The mechanism, the risk of over-toning, and the correct technique are covered at Toning Shampoo.
Blue shampoo does the same for orange in brunettes, and green for red tones.
Where it sits in the rules
Cosmetic — FDA primary category (07) hair colouring preparations.
These are direct dyes, not coal-tar oxidation dyes, so they generally do not shelter under the coal-tar hair dye exemption and are subject to the ordinary colour additive requirements: approved for the intended use, and certified colours from FDA-certified batches.
PPD is normally absent, making this an option for people sensitised to permanent dye — with a patch test still advisable, since direct dyes have their own sensitisation potential.
In the EU, direct dyes are listed with limits in Annex III following SCCS assessment, and methylisothiazolinone is limited to 15 ppm in rinse-off products and prohibited in leave-on ones.
Shelf life
12–18 months after opening. A shampoo base is a robust, well-preserved product; the part that fails first is the dye, which degrades and leaves a bottle that cleans normally and colours less. That is a performance decline, not spoilage.
Discard at separation, a change in smell, or a clear formula gone cloudy.
Related
- Hair Colour — the shelf this sits on, and the rest of it.
- Cosmetics — what the label is legally allowed to say, and the full catalogue.
- The rest of Depositing washes — Colour-Depositing Conditioner · Toning Shampoo.
- Shampoo — the base this is built on, and why it fights the dye.
- Regulatory statements here follow the FDA and EU sources listed on Cosmetics, read 16 August 2026.