Understanding colour values and colour systems: RGB, CMYK, HEX, Pantone and RAL

Colour is a universal language, but communicating it accurately is often more complex than it appears. A colour that looks vibrant on a computer screen may appear duller when printed, or slightly different when applied as paint, plastic, or textile dye. To describe and communicate colour clearly, it is important to distinguish between colour values and colour systems or colour catalogues. RGB, CMYK and HEX specify colours through numerical values for particular media or processes. Other methods of describing colour values include HSV, XYZ and CIE-LAB. Pantone and RAL, by contrast, are standardized colour systems or catalogues whose individual colours can be identified by a reference and described using corresponding colour values. Other examples include Coloro and Archroma colour systems.

RGB, which stands for Red, Green and Blue, is a colour model used to represent colours on digital screens. Smartphones, tablets, computer monitors, televisions and LED displays all use RGB technology. Unlike printed colours, which rely on pigments or inks, RGB works with light. It is an additive colour model because colours are created by adding different intensities of red, green and blue light. When all three components are displayed at maximum intensity, the result is white light. A specific RGB colour is communicated through three numerical values.

You can create different colours by using different values for RGB between 0 and 255.

For Example:

• Black: (0, 0, 0)
• White: (255, 255, 255) 
• Red: (255, 0, 0)
• Green: (0, 255, 0)
• Blue: (0, 0, 255)

One of the major advantages of RGB-based colour reproduction is its ability to display bright, luminous and highly saturated colours. This makes it ideal for digital applications such as websites, presentations, social media content and online shops. However, RGB values describe emitted light on digital devices. When a design created in an RGB colour space needs to be printed or reproduced on a physical object, its values must be converted for the target process, often resulting in slight colour differences.

HEX colours are closely related to RGB. In fact, a HEX code is simply another way of expressing RGB colour information. Instead of using three numerical values for red, green, and blue, it uses a six-character hexadecimal code preceded by a hash symbol. For example, the colour represented as RGB (0, 85, 164) can also be written as #0055A4. Both describe exactly the same colour. 

HEX codes have become the standard notation for web development and digital design because they are compact, easy to share, and universally understood by browsers and design software. When defining brand colours for websites or digital platforms, HEX codes are often included alongside RGB values to ensure consistency across all digital touchpoints. 

While RGB is based on light, printing relies on ink. This is where CMYK comes into play. CMYK stands for Cyan, Magenta, Yellow and Key (Black), the four process colours used in most commercial printing processes. It is a subtractive colour model because the inks absorb, or subtract, portions of light reflected from the paper. A specific CMYK colour is expressed as four percentage values that indicate the amount of each process ink. The more ink that is applied, the darker the resulting colour generally becomes.

CMYK values are the standard way to specify colours for print media such as brochures, product catalogues, magazines, packaging and other printed materials. The four-colour process enables printers to reproduce a wide range of colours using only four inks. However, its colour gamut is more limited than that of many RGB colour spaces. Bright blues, vivid greens and fluorescent colours that appear highly saturated on screen cannot always be reproduced accurately in print. As a result, a design created digitally may look slightly less vibrant once it is transferred to paper.

For brands that require precise colour reproduction, this limitation can present a challenge. Standardized colour systems and catalogues such as Pantone provide physical references and uniquely identified colours that support more consistent communication.

The Pantone Matching System (PMS) is a standardized colour system and catalogue developed to provide a consistent and reliable method of colour communication. Instead of defining a colour only through device- or process-dependent values, Pantone assigns each catalogue colour a unique identification number and provides a physical reference. In printing, many Pantone colours are produced with pre-formulated spot inks. Designers, printers, manufacturers and suppliers around the world can therefore refer to the same catalogue colour. Each Pantone colour can also be associated with corresponding RGB, CMYK, HEX or other colour values, although conversions may only be approximations.

Pantone is particularly important for brand identities. Many well-known companies specify Pantone references for their logos and corporate colours to ensure that the same shade is reproduced consistently regardless of where it is printed. The system is also widely used in packaging, graphic design, textiles, and fashion industries. 

An additional advantage of Pantone is its ability to reproduce colours that fall outside the standard CMYK colour range. Highly saturated oranges, deep blues, metallic effects, and fluorescent colours can often be achieved more accurately using Pantone spot colours than with conventional four-colour printing. 

The Pantone Matching System includes several colour libraries designed for different industries and materials. Although all Pantone systems aim to provide a standardized colour reference, they are optimized for specific applications.

In the graphic arts and printing industry, Pantone Formula Guide Coated (Pantone C) is the most commonly used standard. The "C" stands for Coated, indicating that the colour appearance is based on coated paper. Pantone C colours are frequently used for brand identities, packaging, marketing materials, and increasingly also as a reference for embroidery threads, as they provide a widely recognized and globally accepted colour communication standard.

For embroidery applications, Pantone references are often used as a communication tool between brands, designers, and thread manufacturers. In many cases, embroidery colours are matched against Pantone C references because brand colours are typically defined within the graphic design and printing environment. The embroidery thread is then selected or dyed to achieve the closest possible visual match to the Pantone specification.

The fashion and textile industries mainly work with Pantone Fashion, Home + Interiors (FHI) colour standards. Within this system, colours are often specified as TCX (Textile Cotton eXtended) references. These physical cotton swatches or QTX files allow designers, textile manufacturers, and brands to evaluate colours on an actual textile substrate rather than on paper. Since the appearance of a colour can vary significantly depending on the material, TCX standards provide a more realistic representation for fabrics and garments.

It is important to note that an exact match is not always possible when converting colours between different materials. A Pantone colour printed on paper, displayed on a screen, or reproduced with embroidery thread may appear slightly different due to the characteristics of the substrate, texture, gloss, and colour gamut of the material.

While Pantone dominates the printing and branding world, RAL is one of the most widely used colour standards for physical products, paints, and industrial coatings. Originally developed in Germany, the RAL system has become a widely recognized reference for architecture, construction, manufacturing, and product design throughout Europe and beyond. 

Each RAL colour is identified by a unique numerical code, making it easy for manufacturers and suppliers to specify colours without ambiguity. When a customer requests RAL 7016 Anthracite Grey or RAL 9010 Pure White, suppliers know exactly which colour to produce. 

Unlike RGB, CMYK or HEX values, RAL provides a standardized catalogue of identified colours intended primarily for physical surfaces and materials. The catalogue reference serves as the common language, while an individual RAL colour may also be described by corresponding RGB, CMYK, CIE-LAB or other colour values for particular workflows. These values do not replace the physical RAL reference and may vary according to the conversion method and reproduction medium.

When discussing colour values and colour systems, it is impossible to ignore the concept of a colour gamut. A colour gamut refers to the complete range of colours that a specific device, colour space or printing process can reproduce. RGB and CMYK values only have an unambiguous meaning when the relevant colour space or profile is known. Different technologies and materials have different capabilities, which means that not every catalogue colour or numerical colour specification can be displayed or reproduced identically everywhere.

A modern digital display using RGB technology can reproduce many bright and vivid colours that cannot be achieved with standard CMYK printing. Similarly, Pantone spot colours can often reproduce highly saturated hues that lie outside the CMYK gamut. This explains why a colour may look brilliant on a computer screen but appear less intense when printed. The desired colour simply falls outside the printable range of the CMYK colour space. 

For designers, manufacturers and colour specialists, understanding both categories is essential. Numerical colour values such as RGB, CMYK, HEX, HSV, XYZ and CIE-LAB describe colours for defined methods, colour spaces or processes. Standardized systems and catalogues such as Pantone, RAL, Coloro and Archroma provide named or coded colour references, often supported by physical samples. Distinguishing between them helps set realistic expectations when colours are converted, matched or reproduced across media and materials.

No single method of describing or standardizing colour can meet every requirement. RGB, CMYK and HEX provide numerical colour values for digital and print workflows; HSV, XYZ and CIE-LAB offer further ways to describe and calculate colour. Pantone and RAL are standardized colour systems or catalogues that assign individual references to defined colours, while systems such as Coloro and Archroma serve other markets and applications. A catalogue colour can be linked to different numerical values, but its appearance may still vary across screens, inks, coatings, textiles and other materials. Effective colour management therefore depends on distinguishing the colour reference from its associated values and selecting the appropriate specification for the intended application.

Technical terms

• Colour values
• Colour systems
• Colour models
• Colour standards
• Colour catalogues
• RGB colour model
• HEX colour codes
• CMYK colour model
• Pantone Matching System (PMS)
• Pantone C
• Pantone Fashion, Home + Interiors (FHI)
• Pantone TCX
• RAL colour system
• CIE-LAB colour space
• Colour gamut
• Digital colour specification
• Colour conversion

• Textile colour matching

   

Common descriptions

People often search for:

• What are colour values and colour systems?
• What is the difference between a colour model and a colour system?
• What is the difference between RGB, CMYK and HEX?
• What is an RGB colour code?
• What is a HEX colour code?
• What does CMYK stand for?
• What is the Pantone Matching System?
• What is the difference between Pantone C and Pantone TCX?
• What is Pantone FHI?
• What is the RAL colour system?
• What is the difference between Pantone and RAL?
• Can Pantone colours be converted to RGB, CMYK or HEX?
• Why do colours look different on screens and in print?
• What is a colour gamut?
• Which colour standard is best for textile and embroidery applications?

• How are brand colours communicated to embroidery thread manufacturers?

   

Alternative terminology

Different industries and software providers may use slightly different terminology.

• Colour management
• Colour matching
• Colour measurement
• Colour perception
• Colour reproduction
• Colour conversion
• Spot colours
• Textile colour standards
• Brand colour consistency 
• Digital colour communication