How Pantone Color Matching Works for Silicone Products

Pantone color matching for silicone products is the process of translating a standardized color reference into a pigment formulation that can be reproduced in molded silicone.

The important word is “translating.”

A Pantone number identifies a color target, but it does not provide a ready-to-use silicone pigment formula. Most Pantone references are produced on paper or other defined substrates, while silicone has its own transparency, surface texture, thickness and light-reflection behavior.

For this reason, matching a Pantone color in silicone requires more than selecting a pigment with a similar name. It involves material selection, pigment formulation, trial mixing, molding, visual assessment, instrumental measurement and production control.

A Pantone Number Is a Color Target, Not a Silicone Recipe

Pantone provides standardized color systems that help designers and manufacturers communicate color more consistently. However, different Pantone systems are intended for different materials and applications.

The Pantone Matching System, commonly identified by codes ending in C or U, was originally developed for graphic printing. The Fashion, Home + Interiors system includes references such as TCX and TPG for textiles and product applications.

Pantone itself notes that color appearance changes with the material on which it is produced and that some colors may not be achievable on every material.

A code such as Pantone 186 C therefore means:

• The target is Pantone 186.
• The reference was produced under the conditions defined for the coated-paper system.
• The silicone manufacturer must create the closest practical reproduction in silicone.

It does not mean that the printing-ink formula used for Pantone 186 C can be added directly to silicone.

Printing inks and silicone pigments use different binders, concentrations, processing methods and curing conditions. The Pantone reference communicates the intended appearance, while the manufacturer develops a separate silicone-compatible formulation.

Why a Pantone Color Looks Different in Silicone

Color is not an independent property that remains identical on every object. What people see depends on the interaction between light, pigment, material structure, surface and surrounding conditions.

Several characteristics of silicone can alter the apparent color.

1. Silicone may be transparent or translucent

Many unpigmented silicone materials are naturally transparent or translucent. When pigment is added, light can still travel into the material before being reflected or scattered.

This gives colored silicone a different visual depth from printed ink on opaque paper.

A pale blue silicone part, for example, may appear:

• Lighter when the wall is thin
• Darker when the wall is thick
• More saturated when viewed against a dark background
• More pastel when white pigment or an opacifier is added

The same pigment formulation can therefore appear different in two parts with different thicknesses.

2. Surface finish changes reflected light

A glossy silicone surface produces more direct reflection. This can make the color appear darker, deeper or more saturated at some viewing angles.

A matte or textured surface scatters more light. It may make the same formulation appear:

• Lighter
• Softer
• Less saturated
• Slightly greyer

Color approval should therefore be performed on a sample with the same surface finish as the final product.

3. The base silicone affects the final shade

Not every silicone compound begins with the same visual base.

Depending on its formulation, uncured or cured silicone may be:

• Highly transparent
• Slightly cloudy
• Bluish
• Yellowish
• Translucent white
• Fully opaque

Fillers, stabilizers, curing systems and other additives can influence the base appearance. A pigment formula developed in one silicone grade may not produce exactly the same result in another.

4. Product geometry affects color perception

Curves, ribs, corners and changes in thickness alter the way light travels through and reflects from a silicone part.

A curved product may look lighter along its edges and darker in the center. Deep textures can create shadows that make a color appear more saturated.

This is why a flat laboratory sample and a three-dimensional molded product may not look completely identical, even when made from the same batch of material.

5. Lighting conditions change perceived color

A color approved under daylight may appear different under office lighting, retail lighting or warm household lighting.

Two samples can also match under one light source but separate visibly under another. This phenomenon is known as metamerism.

Professional color evaluation therefore uses controlled lighting rather than relying only on the light available near a desk or production machine.

What Is Added to Silicone to Create Color?

Silicone is normally colored using pigment pastes or color masterbatches designed specifically for silicone rubber.

A color masterbatch generally contains:

• One or more pigments
• A silicone-compatible carrier
• A controlled pigment concentration
• Processing aids where required

The carrier helps disperse the pigment uniformly through the silicone without introducing an incompatible material.

Commercial silicone pigment systems are formulated for particular silicone types. For example, some color masterbatches are designed for high-consistency rubber, while others are intended for liquid silicone rubber. Dow describes silicone color masterbatches as pigments dispersed in a form that can be mixed into silicone compounds, while Wacker identifies several LSR grades as readily pigmentable with compatible color pastes.

The colorant must also be compatible with the curing system. An unsuitable pigment or carrier may interfere with curing, reduce physical performance or create inconsistent color.

Coloring high-consistency silicone rubber

High-consistency rubber, also called HCR or HTV silicone, has a thick, gum-like consistency.

Pigment paste is usually incorporated through mechanical mixing, such as a two-roll mill. The repeated folding and shearing action distributes the pigment through the silicone compound.

The process must achieve uniform dispersion without:

• Introducing contamination
• Overheating the material
• Mixing the wrong silicone grades
• Creating visible pigment streaks
• Changing the approved pigment ratio

Coloring liquid silicone rubber

Liquid silicone rubber is normally supplied as two components, commonly described as Part A and Part B.

Color paste may be introduced through a controlled metering system during injection molding or pre-mixed according to the material and equipment arrangement.

Accurate dosing is important because small pigment changes can produce visible shade differences, particularly in pale, neutral or low-saturation colors.

The Pantone Color-Matching Process

A controlled color-matching process normally follows several stages.

Step 1: Define the exact color reference

The color request should include the complete Pantone designation, not only the number.

For example:

• Pantone 186 C
• Pantone 186 U
• Pantone 17-3938 TCX
• Pantone 17-3938 TPG

The suffix matters because different systems and substrates can display different versions of what may appear to be a similar color.

A current physical Pantone guide or official color chip is preferable to:

• A screenshot
• A photograph
• A website image
• An RGB value
• A hexadecimal code
• A color viewed on a phone or computer screen

Pantone warns that on-screen simulations may not accurately represent its physical standards and recommends using a recent physical reference when a project moves from digital design to a real product.

Step 2: Fix the silicone material

The silicone grade should be selected before final color approval.

The specification may include:

• LSR or HCR
• Platinum-cured or peroxide-cured silicone
• Hardness
• Transparency
• Filler content
• Food-contact or application-specific requirements
• Post-curing conditions
• Surface finish

Changing the silicone material after color approval can change the result, even when the same pigment formula is used.

Step 3: Identify the product conditions

The color technician needs to understand how the final product will be manufactured and viewed.

Important conditions include:

• Minimum and maximum wall thickness
• Glossy, matte or textured finish
• Transparent, translucent or opaque appearance
• Molding temperature
• Post-curing process
• Whether the product is single-color or multi-color
• Whether the silicone is bonded to plastic or metal
• The expected lighting environment

This information determines how the trial sample should be prepared.

Step 4: Create an initial pigment formulation

The technician selects a combination of silicone-compatible pigments based on experience, existing color data and the visual direction of the Pantone target.

A color is rarely produced from one pigment alone.

A muted green, for example, may require controlled amounts of:

• Green pigment
• Yellow pigment
• Blue pigment
• White pigment
• Black or another neutralizing pigment

The purpose of the first formulation is to approach the target closely enough for further measurement and adjustment.

Step 5: Mix the trial compound

The pigment formulation is weighed and mixed into the selected silicone.

Mixing quality directly affects the color result. Poor dispersion can produce:

• Streaks
• Uneven opacity
• Dark pigment spots
• Local color differences
• Different readings across the sample

The trial batch should use controlled weighing, clean equipment and a documented mixing procedure.

Step 6: Mold a physical color sample

Color should be evaluated after the silicone has been cured.

Uncured silicone paste does not necessarily have the same appearance as the final molded material. Heat, curing, surface formation and post-curing can all affect the appearance.

The most useful sample is produced with:

• The actual silicone grade
• The intended molding process
• A representative wall thickness
• The intended surface texture
• The required curing and post-curing conditions

A flat color plaque can be useful for instrument measurement, but a product-shaped sample may also be required for visual approval.

Step 7: Compare the sample with the target

The molded sample is compared with the Pantone reference under controlled lighting.

The evaluator checks whether the sample is:

• Too light or too dark
• Too red or too green
• Too yellow or too blue
• Too vivid or too grey
• Too transparent or too opaque

Visual evaluation is useful because people ultimately judge the finished product with their eyes. However, human perception is influenced by lighting, surrounding colors, fatigue and individual differences.

Instrument measurement is therefore used alongside visual assessment.

Step 8: Measure the color instrumentally

A spectrophotometer measures the light reflected from a sample across a range of wavelengths. The data can then be expressed in a standardized color space such as CIE Lab*.

CIE defines Lab* as a color space that represents lightness and chromatic dimensions and can be used to calculate numerical color differences.

The three main coordinates are:

Coordinate	What it describes	Direction
L*	Lightness	0 is black; 100 is white
a*	Red-green axis	Positive is red; negative is green
b*	Yellow-blue axis	Positive is yellow; negative is blue

These values help the technician understand how the molded sample differs from the target.

For example:

• A higher L* means the sample is lighter.
• A positive difference in a* may indicate that the sample is too red.
• A negative difference in b* may indicate that the sample is too blue.

The pigment formulation can then be adjusted in the required direction.

Step 9: Calculate the Delta E difference

Delta E, written as ΔE, is a numerical expression of the overall difference between two colors.

A smaller Delta E generally indicates a closer match. A larger value indicates a greater overall difference.

However, Delta E is not a complete description of the mismatch. It shows the magnitude of the difference but does not by itself explain whether the sample is too light, red, yellow or blue.

The individual L*, a* and b* differences are still needed for formulation correction.

Several Delta E formulas exist, including:

• ΔE*ab
• CIE94
• CMC
• CIEDE2000, or ΔE00

CIEDE2000 was developed to provide a closer relationship between numerical values and perceived color differences in many practical situations.

There is no single Delta E tolerance that is automatically correct for every silicone product. The accepted limit depends on:

• Color sensitivity
• Product category
• Surface finish
• Transparency
• Measurement repeatability
• Customer expectations
• Production capability
• The Delta E formula being used

A tolerance is only meaningful when the measurement method is also defined.

Step 10: Adjust and repeat

The first molded sample may not meet the target.

The technician adjusts the formulation based on both visual observations and measurement data. A revised batch is mixed, molded and measured again.

Several rounds may be required, especially for:

• Pale neutral colors
• Skin-tone shades
• Highly saturated colors
• Transparent colors
• Colors with low pigment concentration
• Products with varying wall thicknesses

The process continues until the sample falls within the agreed visual and numerical range.

Step 11: Approve a physical master sample

Once the color is accepted, a physical molded sample should be retained as the production master or golden sample.

The approved sample should represent:

• The correct silicone grade
• The final pigment formula
• The required thickness
• The production surface finish
• The final curing conditions

A Pantone chip remains the original design reference, but the approved silicone master becomes the most practical standard for later production batches.

This is because production silicone should be compared with silicone, rather than repeatedly compared only with printed paper.

Step 12: Establish production tolerances

Color approval should define what level of variation is acceptable.

A useful specification can include:

Specification item	Example of what should be defined
Color target	Complete Pantone code and system
Physical reference	Pantone chip and approved molded sample
Silicone grade	Exact material and hardness
Sample thickness	Defined measurement thickness
Surface	Glossy, matte or specified texture
Instrument	Spectrophotometer type or measurement geometry
Illuminant	Agreed evaluation condition
Observer setting	Agreed standard observer
Difference formula	ΔE*ab, CIEDE2000 or another defined method
Tolerance	Agreed project-specific maximum
Visual evaluation	Approved lighting conditions
Post-curing	Defined time and temperature where applicable

Without these details, two parties can measure the same product differently and reach different conclusions.

Why “Exact Pantone Matching” Can Be Misleading

The phrase “exact Pantone match” is often used casually, but physical materials rarely reproduce a printed reference with absolute identity.

There are several reasons.

The Pantone reference may be outside the silicone color range

Some highly saturated, fluorescent or special-effect colors cannot be reproduced with standard silicone pigments.

A visually close alternative may be possible, but the spectral response may still differ from the original reference.

Silicone and paper interact with light differently

Printed paper is generally flat and opaque. Silicone can be translucent, elastic, curved and three-dimensional.

Even when measurement data is close, the materials may not look identical in every viewing condition.

The product may contain multiple thicknesses

A thin silicone edge and a thick silicone center can appear to be different shades despite coming from the same compound.

There may be no single formulation that makes every thickness look identical.

Color tolerance is unavoidable in production

Pigment dosing, silicone batches, mixing, curing and measurement all have normal process variation.

The objective is therefore not theoretical perfection. It is a controlled and repeatable match within an agreed tolerance.

How Thickness Changes Silicone Color

Thickness is particularly important in translucent silicone.

When light enters a thicker section, it travels through more colored material. More light is absorbed or scattered before returning to the observer.

As a result, a thick section can look:

• Darker
• More saturated
• More opaque

A thin section may look:

• Lighter
• Less saturated
• More transparent
• More affected by the background beneath it

For products with large thickness differences, color approval may need to consider several areas rather than one measurement point.

Examples include:

• Suction bowls with thin rims and thick bases
• Silicone bottle sleeves
• Teethers with raised textures
• Seals with thin lips
• Transparent medical components
• Nipple covers with tapered edges
• Multi-depth ice molds

How Surface Texture Changes the Result

A spectrophotometer measures color under a defined optical geometry, but the perceived appearance of a textured product can still vary with viewing angle.

Glossy surfaces create highlights that may make visual assessment difficult. Matte surfaces scatter light and may appear lighter.

This means that a polished color plaque should not be used as the only approval sample for a final product with a heavy matte texture.

The surface condition should remain consistent across:

• Color-development samples
• Approval samples
• Production parts
• Instrument measurements

What Causes Batch-to-Batch Color Variation?

Even after the formula is approved, several production factors can create variation.

Pigment weighing

Small weighing errors can be visible, especially in pale colors where the pigment concentration is low.

Pigment dispersion

The correct amount of pigment can still produce an uneven result if it is not dispersed completely.

Raw-material variation

Different silicone or pigment batches may have small variations in transparency, base tone or color strength.

Mixing equipment

Mixing time, roll gap, batch size and material temperature can affect dispersion.

Molding conditions

Changes in mold temperature, cure time and part thickness may alter the final appearance.

Post-curing

Where post-curing is required, inconsistent time, temperature or airflow may produce differences between batches.

Contamination

Residue from a previous color can affect the next batch. White, pastel and transparent silicone are particularly sensitive to contamination.

Measurement inconsistency

Different instruments, apertures, backgrounds, illuminants and measurement positions can generate different results.

Color control must therefore cover both formulation and process conditions.

Common Mistakes in Silicone Color Matching

Using a screen image as the only reference

Monitors and phones use emitted RGB light. Physical silicone is viewed through reflected or transmitted light.

Pantone explicitly cautions that on-screen representations may not match physical color standards.

Omitting the Pantone suffix

“Pantone 186” is incomplete. Pantone 186 C and Pantone 186 U are not interchangeable references.

Approving the color before molding

The mixed but uncured silicone may not represent the final molded color.

Using a sample with the wrong thickness

A thin color chip may not predict the appearance of a thick silicone product.

Changing the silicone grade after approval

A new material may have a different transparency or base tone.

Comparing colors under uncontrolled lighting

Window light changes throughout the day, while office lamps vary in color temperature and spectral distribution.

Expecting silicone and packaging to look identical

A silicone product, printed cardboard box, plastic accessory and fabric pouch may all use the same Pantone target but still appear different because each material reproduces color differently.

The practical goal is visual harmony, not necessarily identical spectral behavior across unrelated materials.

Failing to define a tolerance

Terms such as “close,” “slightly lighter” or “almost the same” are subjective.

A controlled specification should combine an approved physical sample, a measurement method and a numerical tolerance.

Special Considerations for Food-Contact, Baby and Medical Applications

Pigment selection is not only an aesthetic decision.

For regulated or sensitive applications, the selected color system may need to satisfy requirements related to:

• Restricted substances
• Heavy metals
• Migration
• Biocompatibility
• Food contact
• Cure compatibility
• Traceability
• Heat stability
• Application-specific regulations

A pigment described as suitable for silicone is not automatically suitable for every application.

The compliance review should consider the complete colored compound, including:

• Base silicone
• Pigment
• Pigment carrier
• Additives
• Curing system
• Intended contact conditions
• Final manufacturing process

Increasing pigment concentration to reach a difficult color may also affect opacity, curing or physical properties. Color targets should therefore be reviewed together with performance and compliance requirements.

What Information Is Needed for Reliable Color Matching?

A complete silicone color specification should answer the following questions:

1. What is the full Pantone code and system?
2. Is a physical Pantone chip available?
3. What silicone grade will be used?
4. Is the product transparent, translucent or opaque?
5. What is the product’s wall-thickness range?
6. What surface finish will be used?
7. Will the product be post-cured?
8. Under which lighting should the color be evaluated?
9. Which Delta E formula will be used?
10. What numerical tolerance is acceptable?
11. Which part of the product will be measured?
12. Will a molded golden sample be retained?
13. Are there application-specific pigment restrictions?
14. Must the color coordinate with plastic, metal, packaging or fabric components?

Clear answers reduce unnecessary rounds of color correction and make later batch control more objective.

Conclusion

Pantone color matching for silicone products is not a direct conversion from a printed color number into a fixed pigment recipe.

The Pantone reference establishes the target. The actual silicone formulation must then be developed using compatible pigments, the selected silicone grade, representative thickness, the intended surface finish and the real molding process.

A reliable workflow combines:

• A current physical color reference
• Controlled pigment formulation
• Uniform material mixing
• Molded color samples
• Standardized visual evaluation
• Spectrophotometer measurement
• Lab* and Delta E analysis
• A retained physical master
• Defined production tolerances

The final objective is not to claim an absolute match under every possible condition. It is to create a controlled, visually appropriate and repeatable silicone color under clearly defined manufacturing and evaluation conditions.