How do I create a split-tone effect in GIMP?
Here is an example of the effect I am looking for.
The effect is not a single color, but a gradient map, where everything between black and white is replaced with a transition between two colors. To create this effect in GIMP, you would first set the active foreground and background colors to the colors that you want to map to black and white, respectively:
The source image should have good contrast for best results:
Make sure that the the active gradient is set to "FG to BG (RGB)", which is the default, then from the "Colors" menu, select "Map>Gradient Map":
One way I often achieve a similar look in Gimp is the following:
Here are the original and result:
Image credit: Kelsey's GB Photography