RAL is a system of color definition that classifies colors by a system of numbers and letters. RAL is an independent system not affiliated with any company or brand. The RAL system has been in use since 1927. Using RAL numbers allows for nearly precise matching of colors across different brands of paint. Because RAL is a proprietary system, it is not possible to exactly translate RAL colors to other systems. However, you can get a close match by taking some careful steps.
Ensure that the lighting for your color matching is as close to accurate as possible. If you are matching wall paint, try to perform this matching test in the actual room with both natural light and the light you have in the room.
Hold the RAL color fan beside the paint or color sample at the same angle as the original application. This prevents shadows or reflections from distorting the color.
Sort through the color fan until you have visually identified the closest possible match.
Identify the RAL number for the match.
Consult an online color conversion chart to find the nearest match in the appropriate color system.
Lighting is important to color matching. Colors will appear different in natural light and the artificial light produced by different light bulbs. Always try to recreate the correct environment when matching colors.
Most paint shops will have professional color matching equipment.
There are multiple RAL color systems: RAL Classic, RAL Effect and RAL Design are the most common.