Specify RAL Classic Color
You can specify The Classic Color Collection using its four digit number. The first number is a system code number that identifies the color hue (1=yellow, 2=orange, 3=red, 4=violet, 5=blue, 6=green, 7=grey, 8=brown, 9=white or black). The next three numbers in the four-digit sequence are simply sequential numbers chosen as the color comes into the RAL system. RAL recommends specifying the Classic Collection using both the color name and its color number to prevent any number transposition from causing a mistake. For instance, "melon yellow, RAL 1028" prevents the wrong yellow color from being specified if you use only the numbers.
Specify A RAL Design Color
A number system specifies The RAL Design Colors using only a number system. The system doesn't use color names. It organizes colors around the hue, lightness and chroma (color). RAL Design Color numbers look different than the Classic Color numbers. They are three sets of numbers, each separated from the proceeding set by a space. The first number identifies the hue, the second the lightness and the third the chroma. They are not related to the hue numbers of the Classic color specification. Use all numbers shown on RAL register cards during specification. Never drop zeros.
The RAL Design number 270 30 20 identifies a dark blue with a hue of 270, lightness of 30 and chroma of 20. The structure of the RAL Design system specification numbers follows the color measurement system called called the CIELab designed in 1976 by the Commission International d'Eclairage (CIE). Those with knowledge about the CIELab can use the color numbers to recognize and locate the color within the three-dimension model that the CIELab uses. Understanding the number system is not necessary to specify the RAL-defined color but is important to the manufacturer providing the matching paint.
RAL issues register cards for each color it defines. Because manufacturing practices and environments vary, RAL does not use color tolerances to identify which manufacturers and applications are true RAL colors. RAL recommends consulting a color expert to resolve color disputes involving someone using a RAL register card. Due to the possibility of faded or altered color, keep registration cards covered and away from light to maintain the closest match.