Color systems in the sign craft: RAL and color matching.

Colour is one of the first things a customer judges a sign on — and one of the things that most often causes disagreement if the finished result doesn't match expectations. That is why the sign industry works with standardised colour systems instead of loose descriptions like "dark blue" or "warm grey".

RAL is a colour system originally developed in Germany in 1927 to enable precise and unambiguous communication of colour tones between designer, manufacturer and customer. The modern RAL system comprises 213 different colour shades, each identified by a four-digit number together with the letters "RAL" – for example RAL 9010 (pure white) or RAL 9017 (traffic black).

RAL and NCS colours are typically used on windows, doors, gutters and facade elements, and that's why the RAL code is often already fixed for a building when the sign is to be designed. By asking the customer or architect for the facade's RAL code, you can select a film or paint that matches the facade precisely – instead of guessing from a photograph.

• 01Always ask for a RAL code if the sign should match an existing façade, door, or window.
• 02A colour on a screen can differ from the printed or film-coated result — always use a physical colour swatch or sample when possible.
• 03Some foil producers list their colours with both their own part number and nearest RAL match – use it to compare manufacturers.
• 04Light and weather affect how a colour is perceived outdoors — always assess the final result in daylight.

Alongside RAL the NCS (Natural Colour System) is also used particularly in Scandinavia to describe colours according to their visual properties such as hue black content and colourfulness. The two systems are often used side by side in the construction industry and it is therefore an advantage to be able to convert between them when a customer or architect provides a colour code in one system.

A colour deviation on a sign is rarely a catastrophe but it can cost expensive reproduction and a dissatisfied customer if the sign must be redone because it does not match the facade. Precise colour agreement before production — preferably in writing with a RAL or NCS code — is therefore a small investment that saves time and material in the end.