The colour mode is a setting that determines the depth to which colours can be displayed in an image file. This also affects the size of the file.
The most common colour modes are:
- RGB mode (millions of colours)
- CMYK mode (colours for four-colour printing)
- Lab/CIELab
- Index mode (256 colours)
- Grayscale (256 shades)
- Bitmap (2 colours: Black or white)