The RAL DESIGN system

The RAL DESIGN system was mainly developed for demanding decorative colour design. Thus it is the colour system of choice for architects, designers or ad agencies – in Germany as well as internationally. With its 1624 systematically arranged, colourmetrical defined colour tones the system is a perfect instrument for individual colour designs and quickly found its enthusiasts since the market introduction in 1993. Creative colour designs demand a multitude of colour nuances – RAL DESIGN fulfills that demand with the highest precision.

In 2007 the RAL DESIGN system was revised and now contains 26 new pastel- colour tones, in order to accomadate the rising importance of this area. On the other hand a tightening was conducted in the colour spaces that are darker, less saturated and less useable.

The RAL DESIGN system colour samples are offered in the form of a double fan and as a fan box, as an example.

The systematic build-up

The build-up of the RAL DESIGN system is not arbitrary, rather it follows the internationally used lab-colour measurement system as stipulated in 1976 from the CIE (Commission International d’Eclairage). The colour distances of the individual colours are defined by the CIELAB-colour distance formula, which is also fixed in the DIN 6174 as DIN-norm. The system is thus differentiated from that of competitors. The colours in the RAL DESIGN system are not only systematically arranged by hue, brightness and chroma, but are also, absolutely calculable due to the CIELAB-definition.

Illustration 1 depicts the spacial build-up of the RAL DESIGN system. The hues are arranged in the sequence of the spectrum colours in the wheel. The varying brightnesses, which are possible with hues, are arranged in verticle levels. Illustration 2 depicts one of these levels. The achromatic axis, which constitutes the measure for the brightness, runs through the centre (illustration 3). In illustrations 2 and 3 the term chroma becomes evident. The chroma of a colour is the intensity of its colourfulness, it increases from the central achromatic axis outward, its value on the axis is equal to zero.

Abb. 1: RAL DESIGN systems body of colour	Abb. 2: Colours with a brightness of 50	Abb. 3: Section of the body of colour with the achromatic axis

High Clarity

A large advantage of the RAL DESIGN system over other comparable systems is, despite the 1625 colours, the high degree of clarity and intuitiveness. A colour name (e.g. RAL 010 40 25, see illustration) is easy to find within the spacious CIELAB-colour model, due to its name. The first part of the colour name indicates the angle in the colour wheel, the second part the brightness, and the third the saturation (strength).

In contrast what do the numbers and designations of many other systems mean? The equidistance between the individual colour samples of delta E = 5 is also highly intuitive and clear.

The depicted colour tones in the atlas are not the only available colour tones, but also every colour in between. One only has to specify the desired coordinates (in between values).

Highest Exactness

The RAL DESIGN colours are defined by the colourimetric coordinates HLC (conversion of the cartesian CIELAB-coordinates L*a*b* into the polar coordinates HLC). Thus a colour is clearly described any time, the world over, even without a colour sample present. The adherence to the strictest quality measures are continuously monitored by RAL.

It is important to note that the same conditions must be observed for the comparison colours as were in effect for the original measurement. In other words: CIELAB-colour values are not always the same, rather they fluctuate depending on the measurement device used. For the purpose of maximum quality requirements RAL decided on the following measurement conditions.

Best suitability for a computer colour system

Under the headline of "colour management" the CIELAB-colour model has, at this time, strongly asserted itsself in the area of computers. CIELAB-coordinates clearly describe the appearance of a colour. They are device independent, which differes from RGB-colour values (as an example). A RGB-colour value will be displayed differently on different devices (sRGB, Apple RGB, Adobe RGB,...), with lab-values and activated colour management this should not be the case. Nowadays Macintosh- and Windows-operating system, Adobe Photoshop, Corel Graphics Suite and numerous other programs support the CIELAB-definition of colour.

RAL, RAL C1 DIGITAL 4.0, RAL CLASSIC, RAL DESIGN System and RAL EFFECT are registered trademarks of the RAL German Institute for Quality Assurance and Certification e.V. © DTP STUDIO OLDENBURG