iterm_schemer is a utility to translate the colors in iTerm2 color schemes between dark- and light-background. Using the CIECAM02 color appearance model and the CAM02-UCS color space, iterm_schemer predicts and corrects for the hue, saturation, and lightness shifts that occur when naively reversing the background and foreground colors. It is also capable of bulk-editing the lightness or colorfulness of all colors in a color scheme.
Currently iterm_schemer depends on my own branch of colour-science, which can be installed, along with numpy and scipy, via requirements.txt:
pip3 install -r requirements.txt
An example:
python3 -m iterm_schemer InputDark.itermcolors OutputLight.itermcolors --src-bg dark --dst-bg light --invert
This command line specifies to translate the colors in InputDark to what they should be on a light background. The --invert option goes on to actually invert the lightness of the background and foreground colors, making OutputLight.itermcolors a light-background color scheme.
Adjusting lightness and colorfulness only:
python3 -m iterm_schemer Input.itermcolors Output.itermcolors --j-fac 0.9 --m-fac 0.9
--j-fac 0.9 scales the lightness of all colors in the color scheme to 90% of their original values. --m-fac 0.9 does the same for the colorfulness (roughly, saturation) of all colors. The lightness and colorfulness can be adjusted separately without causing hue shift.