Do it with the GIMPOverview of FeaturesColour Modes

2.1. Colour Modes

Demo:

  1. Open lena_color.jpg.
  2. Select <Image> -> Image -> Mode -> Grayscale
  3. Select <Image> -> Image -> Mode -> RGB
  4. As can be seen, the image remained in shades of gray. However, now colours can be added.

Written by Shlomi Fish