Color Tools are where you can adjust the colors and brightness of an image.You can change the color balance, adjust individual colors or transparency without affecting other colors, and so on. This is the fourth of the four general groups of tools we will look at for GIMP. There will also be some miscellaneous tools.

Links:

https://docs.gimp.org/2.8/en/

https://osdn.net/projects/separate-plus/

http://learn.leighcotnoir.com/artspeak/elements-color/hue-value-saturation/

https://en.wikipedia.org/wiki/Complementary_colors

https://www.ahuka.com/gimp/transform-tools/