About the HSB colour model and saturation
The HSB colour model is an additive colour model used to mix light. Subtractive colour models are used to mix pigments and inks.
- The only difference between the RGB and HSB colour models is 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 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 accounts for colour names such as red, yellow, green or blue.
- Hue can be measured as a location on a colour wheel and expressed in degrees between 00 and 2590.
- Saturation refers to the perceived difference between one colour and another in terms of purity.
- 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 of light.
- On HSB colour wheels, saturation is usually shown to increase from the centre to the circumference.
- Brightness (colour brightness) refers to the difference between a hue that appears bold and vivid at maximum brightness (100%) and then appears progressively darker in tone until it appears black at minimum brightness(0%).
- Colour brightness is often apparent in 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.