How much hair colour is your salon really wasting?

Where does the wasted colour actually go?

It goes down the plughole, unweighed and unrecorded, every time a bowl gets rinsed out at the end of a colour service. No colourist would tell you this never happens — ask around and most will admit some colour gets mixed and never used most days. What’s different is that nobody can say how much, because the moment it happens, the evidence is gone. Not written on the till. Not in the client record. Not on a stock sheet. Just colour that existed a minute ago and now doesn’t.

That absence is the whole problem. You cannot manage what was never measured, and in most salons colour waste has never been measured at all.

Why overmixing is the rational choice, not a mistake

A colourist who mixes a bit more than a head needs is doing exactly what a careful professional should do with the information in front of them. Running short mid-head, with foils already in and a client watching the clock, is one of the worst positions to be caught in. It means a scramble to re-mix and a formula that might not match if it’s guessed under pressure. Against that risk, mixing a bit extra “to be safe” costs nothing that anyone can see in the moment.

That’s the point. The cost is invisible at the exact moment the decision gets made. A tube tells you how much colour is in it, not how much a particular head actually needs, and the two numbers are rarely the same. Nobody is doing sums with a scale in one hand while foiling with the other. So the safe choice — mix a bit extra — is also, quietly, an expensive one, repeated across every chair, every day, with nobody able to see the total it adds up to.

This isn’t a stylist problem to be fixed with a talking-to. It’s a visibility problem. Ask a room of colourists to guess how many grams a full head of highlights needs and the answers will vary widely. Ask the same room to weigh it once and check, and most of the guessing stops being necessary.

Waste doesn’t announce itself. It goes down the plughole looking like nothing happened.

The record that never gets made

A tube-based stock system can tell you how many tubes were opened this month. It cannot tell you how much of each tube ended up on a client’s hair versus down the sink. The two get flattened into one line on a stock order — “colour used” — when really it’s three separate things stacked on top of each other: colour on the head, colour left in the bowl, and colour still in the tube for next time.

Across the wider industry, the scale of this is not small. Salon waste — colour, foils, packaging, product mixed and never used — is well understood inside the trade as a real, ongoing cost, even without a single agreed figure for how much of it is colour specifically. No outside study can tell you what your own back bar loses; only your own bowls can do that. But the shape of the problem is real and worth a proper look, not something imagined.

What changes when the bowl sits on a scale

Nothing changes about how the colour is mixed. What changes is that the bowl sits on a connected scale, so every gram going in is weighed as it happens, not guessed and not estimated after the fact. That weight is costed to the gram and written straight into the client record, so the next stylist who colours that client sees the formula that was actually used last time, not a note that says “usual colour, ask her.”

Across the six working salons already running this way, from London to Saudi Arabia, that’s meant 19,949 colour formulas weighed and costed to date — each one landing in a client record instead of disappearing down the drain unrecorded. The point isn’t to police anyone’s mixing. It’s to make the bowl visible for the first time. Once a salon can see, formula by formula, how much gets mixed against how much a head of that length and density actually needs, patterns become visible in a way they never were before — which formulas tend to run heavy, and which colourists are already weighing close to what a head actually needs.

Tube guess vs weighed bowl

	Guessing from the tube	Weighing the bowl
What gets recorded	Tubes opened per month	Grams actually used, per client, per visit
Who sees last time’s formula	Whoever remembers, or a scribbled note	The next stylist, straight from the client record
Where waste shows up	Nowhere — it’s already down the drain	On the day it happens, against that day’s formulas
What the owner can see about usage	Habit and gut feel	What was actually mixed and used, formula by formula
Who carries the invisible cost	The salon, silently, every day	Made visible, then a decision for the owner

What to do in the first week

Weigh before you change anything. The instinct is to walk in on day one and tell colourists to mix less, but that skips the step that actually works: see what’s happening before anyone tries to fix it. In the first week, the only job is to get every bowl onto the scale and let the numbers build up — no new targets, no comparisons between colourists, nothing that feels like a test being run on anyone.

By the end of the week you’ll have something the salon has never had before: a real number, on your clients, from your colourists’ actual formulas. That’s the moment to look at it properly — not chair by chair, but pattern by pattern. A handful of formulas will usually stand out straight away. Everything after that is a conversation about the number, not a guess about the person.

We’ve written separately about what it actually costs to run colour to the gram once you have that number — this piece is about getting the number in the first place. The plughole has been quiet for a long time. The first week on a scale is just about finally listening to it.

Questions salon owners ask

How much hair colour does the average salon waste?

There’s no reliable per-salon figure, because almost no salon weighs what gets mixed against what actually goes on the head — the waste happens at the bowl and is rinsed away before anyone measures it. Salon waste, including excess colour, is widely understood across the industry to be a real and ongoing cost, but no outside figure can tell you what your own salon is losing. The honest answer for your own salon is to weigh a week of bowls and find out.

Is overmixing colour something to correct with training?

No. Overmixing is usually the sensible choice a colourist makes when they can’t see the true cost of running short mid-head with foils already in. It isn’t carelessness, it’s a rational response to poor visibility. Give colourists a weighed number instead of a guess and the extra tends to shrink on its own, because the decision is no longer being made blind.

What's the difference between colour waste and cost-per-gram?

Cost-per-gram is what you pay for the colour actually used on a client’s head. Waste is the colour that gets mixed, never applied, and poured away unrecorded. You need to weigh the bowl to see either number — once you do, cost-per-gram tells you what a service should cost, and waste tells you what’s being lost before it gets that far.

Do I need different colour or a different way of mixing to reduce waste?

Neither. The colour and the mixing stay exactly as they are. What changes is that the bowl sits on a connected scale, so every gram is weighed as it happens rather than guessed afterwards. That single change makes the formula, the amount used and the amount wasted all visible, and writes them to the client record without asking anyone to work differently at the bowl.

Will weighing colour slow a colourist down mid-service?

It shouldn’t. The scale sits under the bowl and weighs as the colour is mixed, so there’s no extra step, no separate form and no interruption to the appointment. The record is made as the bowl fills, not typed up afterwards.