RAL is a colour-matching system used in Europe, mainly for powder-coated paints, but also for varnish, plastics, and other materials. The RAL system is used to standardize colours, allowing different manufacturers and suppliers to produce consistent colours across a range of products.

The RAL colour system contains over 2000 colours, each identified by a unique four-digit code. These colours are created by mixing a set of standardized pigments and are arranged in numerical order according to their shades, with similar shades grouped together.

RAL colours are used in a wide range of industries, including architecture, automotive, industrial coatings, and graphic design. By using the RAL colour system, manufacturers and suppliers can ensure consistent and accurate colour reproduction across a range of products, making it easier for designers and architects to select and specify colours.

A colour swatch, also known as a colour sample or colour chip, is a small piece of material or card that displays a specific colour. Colour swatches are used to show the colour of a particular paint, fabric, or other material, and they are often used by designers, decorators, and manufacturers to help select and specify colours.

Colour swatches can come in a variety of shapes and sizes, but they typically feature a standardized format that allows different manufacturers and suppliers to produce consistent colours. The most common form of the colour swatch is a rectangular or square piece of paper or card, usually with a standardized size of around 2 inches by 2 inches. The swatch will usually have the name of the colour, a code, and sometimes additional information such as the manufacturer's name or the type of material it represents.

Colour swatches can be used to compare and match colours, to test how a particular colour will look in a particular setting, or to provide a reference for future colour matching. 

Colour samples are small, representative swatches or samples of colours that are used for colour matching, colour comparison, and colour selection purposes. They can come in a variety of forms, such as paint chips, fabric swatches, or plastic colour samples.

Colour samples are commonly used in a variety of industries, including architecture, interior design, fashion, and graphic design. They are especially important in industries where colour accuracy and consistency are critical, such as in printing, manufacturing, and product design.

Overall, colour samples are an essential tool in many industries where colour accuracy is important, as they provide a reliable and consistent way to communicate and specify colours.