At Symphony Coatings our technicians use a mix of their vast colour matching experience coupled with the latest technology to achieve the colours you require. Colour matching is achieved by the use of a spectrophotometer measuring the reflectance data of the supplied dry sample and an algorithm is applied to this data to achieve an acceptable match to this using the tinters supplied. The technician can detect subtle variations in different lighting conditions to correct any slight colour differences. They are tested under the following light standards, D65, TL84, Filament and daylight. Metamerism* can lead to different colour outcomes under different light sources. The Delta E* is the measured difference between the required colour and the suggested colour. As with all systems colour appearance can be affected by many different factors i.e. 1) Film weight 2) substrate 3) drying factors 4) light source 5) application method 6) operator. Whilst this is not a comprehensive list these are some of the factors which can affect the appearance of the colour. All colour matching systems strive to achieve the best match to provide a commercial match to the sample provided.
*Metamerism is the matching of apparent colour of objects with different spectral power distributions. Colours that match this way are called metamers. A spectral power distribution describes the proportion of total light emitted, transmitted, or reflected by a colour sample at every visible wavelength; it precisely defines the light from any physical stimulus. However, the human eye contains only three colour receptors (cone cells), which means that all colours are reduced to three sensory quantities, called the tristimulus values. Metamerism occurs because each type of cone responds to the cumulative energy from a broad range of wavelengths, so that different combinations of light across all wavelengths can produce an equivalent receptor response and the same tristimulus values or colour sensation.
*Delta-E (dE) is a single number that represents the 'distance' between two colours. The idea is that a dE of 1.0 is the smallest colour difference the human eye can see. So any dE less than 1.0 is imperceptible and it stands to reason that any dE greater than 1.0 is noticeable. Unfortunately - and probably not surprisingly - it's not that simple. Some colour differences greater than 1 are perfectly acceptable, maybe even unnoticeable. Also, the same dE colour difference between two yellows and two blues may not look like the same difference to the eye.
Delta-E numbers can be used for:
Although every effort is made by our technicians to get a perfect match, inevitably due to changing environments, colours can be applied with varying differences. This can be due to subtle shade or sheen variances, the conditions of how the product is applied, or the thickness of the coating. To achieve a consistent result we advise you always stir the lacquer thoroughly and try where possible to complete your job from the same batch of paint to minimize any resulting variations.