For objects with glossy surfaces, the specularly reflected light is relatively strong and the diffused light is weaker. On matt surfaces, the specular component is weak and the diffused light is stronger.
People only view diffused light and ignore spectral reflectance. However, when looking at a glossy object, the colour appears different because the mirror-like reflectance from the light source is added to the colour of the object.
So how do we control the quality of colour?
Due to the complex nature of colour, we use measuring methods and equipment that accurately identify the colour that is produced.
A three-dimensional measurement system known as the L*a*b* colour space, developed by the Commission Internationale de l’Eclairage (CIE) and measured using a spectrophotometer, enables colour to be identified numerically and subsequently, be communicated accurately regardless of lighting conditions or other environmental factors.
The mnemonic Lab uses L* to represent lightness while a* represents the red to green axis and b* the yellow to blue axis.