Color theory and color placement: the NCS system and color choice in the painting craft.
From blackness and colorfulness to the right shade on the wall
Introduction
Much of the building painter's expertise is about colour — not just being able to paint evenly, but understanding how colours behave, how they work together, and how to hit the exact shade a customer or architect has asked for. Colour theory is therefore a fixed part of the training, and it is built in Denmark and the rest of the Nordic region largely on the NCS system.
NCS — a system built on what the eye sees
NCS (Natural Colour System) was developed by the Swedish Skandinaviska Färginstitutet and has roots back to research from the 1930s. The system describes colours based on how humans actually perceive them rather than which pigments or mixtures lie behind them. This makes NCS suitable for colour specification because two colours with the same NCS value are perceived the same regardless of which product or producer they come from.
Color psychology and aesthetics
Colour is not just technique. Part of the trade is about understanding how colours affect people and spaces — warm colours can be perceived as inviting and active, cool colours as calm and distant, and light colours can make a room seem larger. As a painter and decorator, you therefore often engage in a dialogue with the customer about what the room will be used for and what mood the colour should create.
- 01Coloured, saturated colours draw attention and can seem dominant in large areas
- 02Light, muted shades give rooms a calm feel and appear larger
- 03Contrasts between walls, ceilings and trim can emphasize architecture or hide unevenness
- 04The same colour can look different depending on light and time of day
NCS versus RAL
Where NCS is built on human colour perception and has a very large number of nuances, RAL is a German industrial standard with a fixed set of 216 colours identified with four-digit numbers. RAL is used especially in industry and painting, while NCS dominates in Scandinavia for buildings, interiors and architecture. As a painter you encounter both systems, and it is important to be able to translate between them when a customer comes with a code from one system but the product must be mixed according to the other.
| System | Build-up | Typical use |
|---|---|---|
| NCS | Perceptual scale for blackness, colour saturation and colour tone | Buildings interiors architecture in the Nordic region |
| RAL | 216 fixed, numbered standard colours | Industry, metal, lacquering |
From colour card to finished blend
Today most paints are mixed by machine. A colour formula is saved in the system and the machine doses pigment paste according to the formula so the same shade can be matched again and again — even years after the original task. This makes it possible to repaint a single corner without visible colour difference and is a great improvement compared to earlier when the colour had to be mixed by hand each time.
Colour matching and colour analysis
Part of the more advanced part of the trade is colour matching and colour analysis — for example when you need to recreate a specific, often old, shade on a facade or in a heritage building without a formula. Here you work backwards: you analyse the existing colour, assess its hue, darkness and saturation and work your way to a mix that matches. It requires a trained eye and understanding of how light and age affect colour over time.
“Color coding keeps areas separate (e.g. toilet and tables) so you don't cross-contaminate and move bacteria between areas.”