Use gowall in Scripts
Preview all of the 25 built in Themes​
Lets say you want to see how the all of the colorschemes of the 25 built in themes look like on an image. We can easily do that with a small bash script.
#!/bin/bash
themes=$(gowall list)
input_path="/home/<name>/Pictures/NOBORDER.png"
while IFS= read -r theme; do
  gowall convert "$input_path" -t "$theme" --output "/home/<name>/Pictures/gowall/Themetest/$theme"
done <<< "$themes"
The output of the above script will be the following, with the names of the images being the themes that your image got recolored to:
1. catppuccin.png
2. nord.png
3. rose-pine.png 
4. everforest.png
....
Load a Theme dynamically in the runtime via .json file​
Lets say you have a way to generate a .json with hex colors (probably via another script) and dont want to define them in ~/.config/gowall/config.yml. Now you can pass .json with a certain interface into gowall.
gowall convert ~/Pictures/img.png -t test.json
gowall convert ~/Pictures/img.png -t ~/clr/test.json # relative path
The test.json must have the following interface :
{
    "name": "MyTheme",
    "colors": [
        "#F5E0DC",
        "#F2CDCD",
        "#F5C2E7",
        "#11111B"
    ]
}