HSB colour model

About the HSB colour model

The HSB colour model is an additive colour model used to mix light. Subtractive colour models are used to mix pigments and inks.

  • The difference between the RGB and HSB colour models is limited to the way colours are represented in terms of colour notation and dealt with in software and apps.
  • Both the HSB and RGB colour models deal with how to mix red, green and blue light to produce other colours.
  • HSB is popular because it provides an intuitive way to select and adjust colours when using applications such as Adobe Creative Cloud for design, photography or web development.
  • The HSB colour model is popular because it provides an intuitive way to select and adjust colours in software applications used for graphic design, web development and photography.
  • Whilst RGB relies on adjusting the amount of red, green and blue needed to produce other colours the HSB colour model relies on adjusting hue, saturation and brightness.
  • Both the RGB and HSB colour model can be used to describe any colour on a TV, computer or phone.

In the HSB colour model:

  • Hue refers to the perceived difference between one colour and another and is usually described by using names such as red, yellow, green or blue.
    • Hue can be measured as a location on an HSB colour wheel and expressed as a degree between 00 and 3600.
  • Saturation refers to the perceived difference between one colour and another in terms of vividness.
    • Saturation is measured between a fully saturated colour (100%) and an unsaturated colour that appears dull and washed out until all colour disappears leaving only a monochromatic grey tone (0%).
    • A fully saturated colour is produced by a single wavelength or a narrow band of wavelengths.
    • On HSB colour wheels, saturation is usually shown to increase from the centre to the circumference.
  • Brightness (colour brightness) refers to the difference between the way a colour appears to an observer in well-lit conditions compared with its subdued appearance when in shadow or when poorly illuminated.
    • Brightness can be measured as a percentage from 100% to 0%. As the brightness of a fully saturated hue decreases it appears progressively darker and achromatic.