As we saw in the previous section, colour is essentially a 3 dimensional quantity. It can be represented by 3 values, red, green and blue. Each unique combination of red, green and blue creates a unique colour.
You could think of these values as axes in a 3 dimensional space, where each point in space is a particular colour. We call this space the RGB colour space.
There are other ways to represent colours. They typically use 3 values, but rather than red, green and blue they use a different set of values (we call this a different colour space). Here are the main ones
- RGB as described above
- Greyscale images only contain shades of grey, with no colour (like black and white photographs).
- CMYK colour spaces are used in printing, where cyan, magenta, yellow, and black inks are used to create colours.
- HSL (hue, saturation, lightness) colour spaces represents a colour as a hue (that represents the basic, underlying colour), saturation (that represents how pure the colour is), and lightness (how light or dark the colour is).
- Luminance/chrominance colour spaces represents colours using a brightness component, and two other values that represent chromatic (colour) component.