I would like to give the ‘Orange & Teal’ look to some pictures using only GIMP. I must remark, the question is specifically restricted to GIMP.
My question is simple but here is some background. ‘Orange and Teal’, also called ‘The Blockbuster Look’ is the practice of color grading pictures and movies in a simplified palette where shadows are turned into blue and lights are given an orange tone. Hated by many, it is being abused in Hollywood productions more and more, but as any other technique it also can be used very creatively to achieve kind of a warm sunset look.
Using the Curves tool you can use curves to achieve this effect.
To make a color adjustment with curves, there are three channels that you can work with: Red, Green or Blue. To get the other colours in the spectrum, you have to mix these by either adding or subtracting various amounts of red, green or blue.
Luminance Curves Adjustment for Teal & Orange Look:
Red Curves Adjustment for Teal & Orange Look:
Green Curves Adjustment for Teal & Orange Look:
Blue Curves Adjustment for Teal & Orange Look:
What you are doing is adding “Teal” to the shadows by subtracting red (to get cyan) and adding blue to the darker tonal range of the image. To get “Orange” into the highlights you subtract blue (to get yellow) from the highlights and add some red. If you get a slight magenta cast in the highlights you can add some green to compensate.
Source : Link , Question Author : Mephisto , Answer Author : Ovaryraptor