Colour perception depends on the colour background of the sample. Also structure, gloss and metallic effects influence the perceived colour, asserts Vijaya Shanbhag.


Colour is something which makes the object more appealing, attractive and gives the pleasure of observation. The Committee on Colorimetry of Optical Society of America defines colour as visual sensation arising from the stimulation of retina of the eye. Thus it is defined as a psychophysical-psychological response to a physical stimulus.


Colour may have different meanings to different people. To a chemist it may be a chemical compound, a dye or a pigment; to a physicist it is scattering and absorption of light or reflectance spectra of the object; to a physiologist it is a measurable activity of nerves, to a psychologist it is a complex process in brain of interpreting the nerve signal. To the artist and others it is a means to create sensation in the mind of the observer. For e.g., the colours as red and yellow create the sensation of warmth. Green and blue are associated with the feeling of coolness. Colour harmony in wall paints; curtains and furniture make room cheerful, and comfortable. Perception of colour includes source of light, object that is illuminated and eye and brain that perceive the colour. A source of light is characterised by the energy that is radiated at different wavelengths, i.e., by its spectral power distribution.


The modification of incident radiations depends on the nature of colourants in object. This is related to chemistry of dyes.


The radiant energy reflected is absorbed by photosensitive pigments in retina of the eye. The photosensitive detectors on retina are called as rods and cones from their shape. The rods detect the light but have no ability to specify the colour. The colour is detected by cones.


The colourists in today's commercial environment has to choose from a vast range of available colourants, the most effective recipe to achieve a commercially acceptable match with the correct physical qualities to satisfy his customers requirements. He has also to ensure that subsequent batches are within acceptable tolerances for depth, shade, and hue. Computer colour matching systems can be used to achieve success in all the above areas and will help increase productivity and reduce costs.



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About the Author


The author is a practicing Textile Consultant and Colour Matching expert.