How can I swap colors with GIMP?

I have made an image with three colors: RGB

I want to swap each channel to a specific color. Is there a way to do that efficiently with GIMP?

Example:

I would like:

• Blue: #434343
• Red: #EEEEEE
• Green: #BBBBBB

3 Answers

For GIMP 2.6.12, Just use Colors -> Map -> Color Exchange

Try Filters -> Colors -> Map -> Color Exchange... in RGB mode.

You should be able to replace one color with another easily.

To directly modify how each channel is interpreted, use Colors -> Components -> Channel Mixer.

To get what you want, you would select

• Blue:
  • Red: 26.3
  • Green: 26.3
  • Blue: 26.3
• Red:
  • Red: 93.3
  • Green: 93.3
  • Blue: 93.3
• Green:
  • Red: 73.3
  • Green: 73.3
  • Blue: 73.3