What is Metamerism and does it matter ??
What Is Metamerism and does it matter ? Metamerism is a phenomenon that occurs when two colour’s appear to match under one lighting condition, but not when the light changes. Metameric matches are quite common, especially in near neutral colours like greys, some white and pastel shades, even some dark colours. As colour’s become lighter or more saturated, the range of possible metameric matches becomes smaller.
The reason for this phenomenon lies in the light source and the way the object reflects light to give us the perception of colour.
Natural and manmade, colorants are everywhere. They are the inks we put down on paper, the dyes we use to colour fabrics, the pigments we use in paint and plastics, and even the chlorophyll found in plant leaves. Dying your hair or clothing changes the colour’s of light that are absorbed or reflected, therefore the colour’s we perceive. This is why the paint on your wall at home can appear different with differing light conditions, soft furnishings, carpets, curtain, bedding can all create a different cast or shade to painted surfaces.
Magnolia emulsion paint is often a classic example of metamerism it can often have a pink cast or a light a green tinge. Over the years a number of people have come back in saying the paint has changed colour from the same tin which is impossible particularly after being stirred prior to application. Upon questioning we often find the paint has been used on staircase, hall and landings where often you get three differing amounts of light, possibly lighter in the hallway, upstairs and on the landing less or no natural light and a colour can appear different.
I was once called to visit a home some years ago as a humble representative of the paint manufacturer I worked for, Mrs Jones lived in an identical house to Mrs Smith. Mrs Smith had purchased a vibrant red for the feature wall of a Victorian semi, bold statement colour looked great !! Mrs Jones liked it so much she wanted the same effect … Unfortunately Salmon pink in her house. we painted a piece of copy paper allowed it to dry over a tea and biscuit ( Thank you ) went 2 doors along held it against Mrs Smith’s wall Bold Red just what Mrs jones wanted, only by doing this could I convince them the colour was right and metamerism was at play. Differing soft furnishings, carpet throwing a new light on the subject.
Different surfaces absorb and reflect light differently, giving a different colour appearance. Glossy objects reflect light directly, giving the colour a shiny appearance, while matte objects scatter reflected light in all directions. Gloss and Matt paints are a good example of this phenomenon. You can ask the paint store to mix the same colorants into each, but when you put them on the wall side by side, the colour will appear to be different.
A great example of Metamerism in the images below.
