1. Archlinux:

yay -S hellwal

2. Mac/Linux via Homebrew:

brew install hellwal

3. NixOS, nixpkgs unstable:

environment.systemPackages = [
  pkgs.hellwal
];

Clone git repo, run make command and you are ready to go! - you just need a C compiler and gnumake!

git clone https://github.com/danihek/hellwal && cd hellwal && make

Run this with your wallpaper image:

hellwal -i [image]

You can also randomly pick an image from a given directory like this:

hellwal -i <folder> --random

Generated templates are saved in ~/.cache/hellwal/.

[INFO] - if you got hellwal from the AUR, examples of default templates can be found in /usr/share/docs/.

There are also examples in the templates folder. They look more-less like this:

# Main
background='%%background%%'
foreground='%%foreground%%'

# Path
wallpaper_path='%%wallpaper%%'

# Colors
color0='%%color0.hex%%'
color1='%%color1.hex%%'

# ... and so on and so forth.

color15='%%color15.hex%%'


# RGB
backgroundRGB='%%background.rgb%%'
foregroundRGB='%%foreground.rgb%%'

color15butRGB='%%color15.rgb%%'

You can get any generated color for values 0 to 15.

After the color keyword, you can specify the format: hex, rgb, or a single rgb channel. By default, the template output is in hex.

Alongside colors, you can specify some variables to make them more suitable for your needs. For now these variables are available:

alpha is ignored for single rgb channels.

Chain HSL (hue, saturation, lightness) adjustments and RGB filters without changing the base palette. Operations apply from left to right:

%% color1.saturate(0.2).lighten(0.1).hex %%
%% background.sepia(0.5).contrast(1.2).rgb alpha=0.8 %%

Factors must be nonnegative; all arguments must be finite. Results clamp to the valid color range after each operation. HSL adjustments add percentage points: lighten(0.2) adds 20 points of lightness. RGB filters work on sRGB channels.

Use color0–color15 or the existing color aliases. Finish the chain with .hex, .rgb, .r, .g, or .b (default: hex), then optionally append alpha=0.5. Hex output omits #; alpha is ignored for individual channels. Invalid operation expressions warn and remain visible in the generated file.

You can use the --json argument to suppress any other output and write colors to stdout in JSON format. You can then manipulate the output with jq. For example:

hellwal -i [wallpaper] --json | jq '.'

You can set your own theme, re-run it anytime and apply it to your config or other programs! It can be a previously generated palette from an image, gruvbox, Tokyo Night, or anything you want! For example, gruvbox theme:

%% color0  = #282828 %%
%% color1  = #cc241d %%
%% color2  = #98971a %%
%% color3  = #d79921 %%
%% color4  = #458588 %%
%% color5  = #b16286 %%
%% color6  = #689d6a %%
%% color7  = #a89984 %%
%% color8  = #928374 %%
%% color9  = #fb4934 %%
%% color10 = #b8bb26 %%
%% color11 = #fabd2f %%
%% color12 = #83a598 %%
%% color13 = #d3869b %%
%% color14 = #8ec07c %%
%% color15 = #ebdbb2 %%

Save the text above as a file or copy gruvbox from this repo and just run hellwal:

hellwal --theme ./themes/gruvbox.hellwal

I recommend putting all themes in the default theme folder ~/.config/hellwal/themes. This way, you can provide the theme name without specifying the path, and hellwal will pick it up automatically. Of course if you want, you can also set a different theme folder. For example:

hellwal -t gruvbox.hellwal --theme-folder ~/dotfiles/configs/hellwal/themes

hellwal -i wallpaper.jpg -t gruvbox.hellwal --override-colors color1,color2,background

This copies matching image-palette slots into the theme: image color1 replaces theme color1, and so on. Select color0–color15, background (color0), or foreground, cursor, and border (all color15). Separate names with commas; duplicates are harmless, and repeated --override-colors options combine their selections. Empty or unknown selectors are errors.

Image colors are sorted and their bright variants prepared before copying. Without adjustment flags, unselected theme colors stay unchanged and mixed mode does not automatically darken the palette. Explicit modes, inversion, offsets, grayscale, static foreground/background, and contrast checks apply to the whole merged palette afterward, so they can also change unselected colors. For example:

hellwal -i wallpaper.jpg -t gruvbox.hellwal --override-colors color1,color2 --light

Both --image and --theme are required. Theme paths, named themes, and --theme-folder work as usual. With --random, only the image is chosen randomly; the specified theme stays fixed. wallpaper in templates/JSON refers to the image. The source theme is never rewritten, and only the raw image palette is cached. Combining image and theme without --override-colors remains an error, and --dominant-background still cannot be combined with themes.

Neon mode boosts colors to make them look more vibrant and bold. Sometimes it's a pain in the EYE, but it often looks better. Turned off by default.

hellwal -i [wallpaper] --neon-mode

You can select -d/--dark or -l/--light mode on any given image, theme, etc., no matter if it's generated from an image or from a theme file. There is also --color mode.

hellwal -i [wallpaper] --dark

Use the wallpaper's most common color for the background instead of the darkest palette color:

hellwal -i [wallpaper] --dominant-background

hellwal -i [wallpaper] --light

hellwal -i [wallpaper] --color

The best thing about it is that you are able to combine all of these together. Usually it's not a good idea, but sometimes you can achieve some crazy color combinations!

hellwal -i [wallpaper] --color --light --dark

Also, you have a couple of cool arguments to manipulate how colors will be computed:

• you can darken all colors by specifying --dark-offset from 0-1 (the higher the value, the darker the colors):

hellwal -i [wallpaper] --light --dark-offset 0.5

• same with --bright-offset (the higher the value, the brighter the colors):

hellwal -i [wallpaper] --bright-offset 0.5

• invert colors with --invert:

hellwal -i [wallpaper] --light --invert

• specify grayscale, if you want monochromatic colors, with --gray-scale:

hellwal -i [wallpaper] --color --gray-scale 0.8

• ensure colors are readable against the background with --check-contrast:

hellwal -i [wallpaper] --check-contrast

With --script or -s you can run a script (or any shell command) after hellwal.

Note: it will only run if hellwal does not encounter any errors.

If you want your new terminals to open with a previously generated or specified color palette, add these templates to your ~/.config/hellwal/templates/ folder:

• variables.sh
• terminal.sh

Run hellwal with an image or theme to generate the output scripts from the templates.

Then in .bashrc, add following lines:

source ~/.cache/hellwal/variables.sh
sh ~/.cache/hellwal/terminal.sh

• variablesfish.fish
• terminal.sh

Then add this to your fish config:

source ~/.cache/hellwal/variablesfish.fish
sh ~/.cache/hellwal/terminal.sh

• dylanaraps - for pywal and other amazing stuff he created.