Colour Approval: Pantone, Lab Dips and Delta E

Colour is the single most disputed line in apparel development, and almost all of the disputes are avoidable. They come from three specific errors: quoting a Pantone number without its system, writing a Delta E tolerance without naming the formula, and approving in the wrong light. This page fixes all three. It sits inside sourcing apparel direct from factories and pairs with where lab dips sit in the sampling calendar, because colour development runs on its own clock and has to start early.

Pantone TCX, TPG and the discontinued TPX

The three Pantone textile systems a brand will encounter. Cost figures are indicative guide prices for a full fan or chip set.

The reason TCX is the production standard is not brand preference, it is physics. A dyed cotton swatch and your dyed cotton jersey scatter and absorb light in a comparable way. A printed paper chip does not. Ask a dyehouse to match a paper chip on cotton and you are asking it to match across substrates, which is where the argument starts.

TPX is the quiet problem. It was withdrawn in 2014, but studios keep old fan decks and factories keep older ones. Because TPX and TPG share overlapping numbering while looking different, a designer reading a legacy TPX chip and a dyehouse reading a current TPG or TCX chip can be looking at the same number and different colours.

Two rules follow, and neither costs anything:

1. Always specify the code and the system. "PANTONE 19-4052 TCX Classic Blue" is a specification. "19-4052" is an invitation to guess.
2. Replace guides every 12–18 months. Pantone swatches fade with light and handling, and a faded standard is worse than no standard, because everyone believes it. Store them closed, out of daylight, and date the box on arrival.

Delta E acceptance thresholds for apparel colour approval

Delta E (ΔE) is the numeric distance between two colours. Smaller is closer.

Delta E acceptance bands and their commercial use. Perception thresholds are approximate and depend on the formula used.

The practical working rule: ΔE ≤ 1.0 on hero and brand colours, ΔE ≤ 2.0 on secondary components. A hero colour is one a customer will see across multiple garments or compare against a website image. Secondary components are rib, thread, zip tape, drawcord and labels, where the eye is far more forgiving. Tightening every component to 1.0 adds lab dip rounds and cost across the entire bill of materials and buys almost nothing.

Why a Delta E number is meaningless without the formula

This is the technical point most brand-side colour specs get wrong, and it is the one that decides arguments.

ΔE values calculated with different formulas are not comparable. The same two physical samples can measure 1.8 under one formula and 0.9 under another. The four you will meet:

• CIE76 (ΔE*ab) — plain Euclidean distance between two points in CIELAB space. Simple, and poorly matched to human perception, especially in saturated regions. A red at CIE76 1.5 and a pale grey at CIE76 1.5 do not look equally close.
• CIE94 — adds weighting terms for lightness, chroma and hue, and has a textile parameter set. Better, and superseded.
• CMC(l:c), usually CMC(2:1) — developed by the Colour Measurement Committee of the Society of Dyers and Colourists specifically for textiles. It defines a perceptual ellipsoid around the standard rather than a sphere, which is why it tracks textile colour judgement far better. This is the formula most dyehouses and QC labs actually use.
• CIEDE2000 (ΔE₀₀) — the modern CIE recommendation, with the best overall perceptual correlation.

So write the tolerance in full: "ΔE CMC(2:1) ≤ 1.0 under D65/10°." Formula, tolerance, illuminant, observer angle. A CMC 2:1 colour tolerance written that way is enforceable. A spec that says only "Delta E under 1.0" is not, because the dyehouse will use whichever formula passes and be technically correct.

The lab dip approval process, round by round

A lab dip is a small piece of your actual base fabric dyed to a trial recipe. The workflow is short and the calendar is not.

1. You issue the dip request with the Pantone code and system, the base fabric, the fibre content, the dye class and the finish.
2. The dyehouse produces two or three recipe variants and returns physical dips, usually with spectrophotometer readings.
3. You assess in a light booth against a current TCX standard, under the named illuminants.
4. You approve, or you comment (typically "too red", "too dark", with the measured ΔE and direction) and the dyehouse re-dips.
5. On approval, the dip is signed, dated and matched: one copy to the dyehouse, one to you. Bulk is then measured against the approved dip, not against the Pantone chip.

Costs and rounds: $15–50 per colour per round, 5–10 business days per round, 2–3 rounds standard. Saturated reds, neons and deep navies routinely take 4–5 rounds, because those shades sit near the edge of the achievable dye gamut, need heavy dye loading, and respond non-linearly to small recipe changes. Deep navies in particular are hard to hold consistently across lots and are prone to crocking failures at the same time.

Worked example: colour calendar and cost for a six-colour range

Five standard colours at three rounds, one hero red at five rounds, at $32 per dip.

The money is trivial. The seven weeks is not. That hero red now sits on the critical path in front of bulk dyeing, which itself adds 4–8 weeks when the colour is custom. Start colour development the same day you release the proto request, not after fit is settled, or the red will decide your ship date. And remember each colour carries its own dye-lot minimums and MOQ economics at bulk, which is a separate constraint on how many colours the range can carry at all.

Metamerism, illuminants and why approval happens in a lightbox

Metamerism is when two samples match under one light source and visibly differ under another. It happens because the two dye recipes have different spectral reflectance curves even though their tristimulus values match under the reference illuminant. It is not a defect in either sample. It is a defect in the recipe.

Standard practice is to assess in a light booth under a defined set of illuminants:

• D65 — 6500 K average daylight. The primary reference for apparel.
• TL84 — European and Asian retail fluorescent.
• CWF (cool white fluorescent) / UL3000 — US retail.
• Illuminant A — incandescent and tungsten, warm.
• Horizon and UV — supplementary checks.

Judge under D65 first, then cross-check under the retail source your goods will actually be sold under and one warm source. A pair that matches under D65 and separates under CWF will separate on the shop floor.

Approve only in the booth, only against a current TCX standard, only on the correct substrate. Non-standard lighting is cited as the cause of 30–40% of disputed lab-dip rejections, which makes a light booth one of the highest-return pieces of equipment a small brand can buy. Approving a dip on an office desk next to a window is not colour management, it is an opinion under an unrepeatable illuminant.

How the dye method limits the colour consistency you can buy

Some colour tolerances are impossible on some processes, and no amount of specification will fix that. The dye method sets the ceiling.

The blank market is where that trade-off is easiest to see, because whole ranges are built on it: see garment-dyed blank styles and their dye economics.

Chemistry matters as much as stage. Reactive dyes form a covalent bond with cellulose and give excellent wash and rub fastness on cotton with vibrant, even shades. Pigment dyes are not dyes at all: pigment sits on the surface held by a binder resin, which is cheaper, works on blends, and fades with washing by design. Batch-to-batch shade variation on pigment is normal and must be written into the tolerance rather than treated as a defect at inspection. Full detail on both, plus the MOQ and cost implications, is in dyeing methods and fabric specification.

This is also where colour approval hands off to quality control: shade variation between panels is a major defect under the standard apparel AQL scheme, so the tolerance you write here is the tolerance an inspector will enforce later. See shade variation as a major defect at inspection.

The colour spec checklist

Everything below belongs on the colourways page of a tech pack, component by component:

1. Pantone code and system for every component, written in full.
2. Formula, tolerance, illuminant and observer: "ΔE CMC(2:1) ≤ 1.0 under D65/10°."
3. Tiered tolerance: 1.0 on hero and brand colours, 2.0 on secondary components.
4. Substrate and dye class named on the dip request, matching the bulk fabric.
5. Assessment conditions: light booth, D65 primary, plus one retail and one warm illuminant.
6. Approved dip is the bulk standard, signed, dated and held in matched copies.
7. Lot-to-lot shade banding reported before cutting, with the accepted band defined.
8. Guide replacement date logged, on a 12–18 month cycle.

Definitions for lab dip, shade band, metamerism and D65 are collected in the Yarnstick glossary of sourcing terms.

Frequently asked questions