monobiome/README.md

Monobiome

monobiome is a minimal, balanced color palette for use in terminals and text editors. It was designed in OKLCH space to achieve perceptual uniformity across all hues at various levels of luminance, and does so for eight monotone bases and eight accent colors (plus one zero chroma default base). Each of the monotone base colors (named according to a natural biome whose colors they loosely resemble) are designed to achieve identical contrast with the accents, and thus any one of the options can be selected to change the feeling of the palette without sacrificing readability.

(Preview of light and dark alpine theme variants)

The name "monobiome" connects the palette to its two key sources of inspiration:

• mono-: monobiome is inspired by the monoindustrial theme, and attempts to extend and balance its accents while retaining similar color identities.
• -biome: the desire for several distinct monotone options entailed finding a way to ground the subtle color variations that were needed, and I liked the idea of tying the choices to naturally occurring environmental variation like Earth's biomes (even if it is a very loose affiliation, e.g., green-ish = grass, basically).

Palette

The monobiome palette is fundamentally a set of parameterized curves in OKLCH color space. Each color identity has one monotone curve and one accent curve, both of which have fixed hue values and vary from 10% to 98% lightness. Monotone curves have fixed chroma, whereas the accent curves' chroma varies smoothly as a function of lightness within sRGB gamut bounds.

Chroma curves	Color trajectories

Palette

There are eight monotone-accent pairs, plus a single grey trajectory:

Monotone / biome	Accent color	Hue
alpine	grey	n/a
badlands	red	29
chaparral	orange	62.5
savanna	yellow	104
grassland	green	148
reef	cyan	205
tundra	blue	262
heathland	violet	306
moorland	magenta	350

The alpine/grey curve has zero chroma (and is thus invariant to hue), varying only in lightness from dark to light grey.

Concrete themes

Dark themes	Light themes

Themes are derived from the monobiome palette by selecting a monotone base (the "biome"), a base lightness, and a contrast level. Although one can use arbitrary contrast metrics, OKLCH distance (Euclidean distance in OKLab) is designed to capture perceptual distinction. As such, perceptually uniform themes under arbitrary monotones can be generated by calculating the accent colors equidistant from that base. This is equivalent to determining the points at which a sphere centered at the monotone base intersects with the accent curves; the radius of such a sphere effectively determines the theme contrast, and the colors on the sphere surface are equally perceptually distinct relative to the background.

The following plots show the intersection of the sphere centered at a fixed background color (alpine biome with a lightness of 20) under variable radii:

	-l 20 -d 0.3	-l 20 -d 0.4	-l 20 -d 0.5
Color visualization
Editor preview

In short, the base lightness (-l) dictates the brightness of the background, and the contrast (-d) controls how perceptually distinct the accent colors appear with respect to that background. These are free parameters of the monobiome model: themes can be generated under arbitrary settings that meet user preferences.

The "soft" harshness level uses monotone shades closer to the mid-shade (lightness level 55), whereas "hard" harshness uses shades further from it. Once the biome and harshness level are chosen, we're left with a bounded monotone range over which common theme elements can be defined.

Applications

When generating full application themes, fixed lightness steps are used in the chosen monotone trajectory to establish consistent levels of distinction between background layers. For example, the following demonstrates how background and foreground elements are chosen for the monobiome vim/neovim themes:

Note how theme elements are mapped onto the general identifiers bg0-bg3 for backgrounds, fg0-fg3 for foregrounds, and gray for a central gray tone. The relative properties (lightness differences, contrast ratios) between colors assigned to these identifiers are preserved regardless of biome or harshness (e.g., bg3 and gray are always separated by 20 lightness points in any theme). As a result, applying monobiome themes to specific applications can effectively boil down to defining a single "relative template" that uses these identifiers, after which any user-provided parameters can be applied automatically. You can read more about how themes are created in DESIGN.

Usage

This repo provides relative theme templates for kitty, vim/neovim, and fzf in the templates/apps directory, along with concrete themes in app-config/. You can also find raw palette colors in templates/apps/groups/ if you want to use them to define static themes for other applications.

Each of the files in the app-config/ directory are named according to

<harshness>-<biome>-monobiome-<mode>.<ext>

For example, monobiome-tundra-dark-soft.vim is the Vim theme file for the dark tundra variant with a soft harshness level.

Applications

• kitty

  Find kitty themes in app-config/kitty. Themes can be activated in your kitty.conf with

  include <theme-file>
  

  Themes are generated using the kitty theme template.

• vim/neovim

  Find vim/neovim themes in app-config/nvim. Themes can be activated by placing a theme file on Vim's runtime path and setting it in your .vimrc/init.vim with

  colorscheme <theme-name>
  

  Themes are generated using the vim theme template.

• fzf

  In app-config/fzf, you can find scripts that can be ran to export FZF theme variables. In your shell config (e.g., .bashrc or .zshrc), you can source these files to apply them in your terminal:

  source <theme-file>
  

  Themes are generated using the fzf theme template.

• Firefox

  Firefox themes for all monotone backgrounds are publicly listed as Mozilla add-ons, and switch between light/dark schemes based on system settings. You can also download raw XPI files for each theme in app-config/firefox/, each of which is generated using the Firefox manifest.json template.

  Static light and dark are additionally available.

  

Switching themes

symconf is a general-purpose application config manager that can be used to generate all monobiome variants from a single palette file, and set themes for all apps at once. You can find example theme templates in templates/groups/theme, which provide general theme variables you can use in your own config templates.

For instance, in an app like kitty, you can define a template like

# base settings
background           f{{theme.term.background}}
foreground           f{{theme.term.foreground}}

selection_background f{{theme.term.selection_bg}}
selection_foreground f{{theme.term.selection_fg}}

cursor               f{{theme.term.cursor}}
cursor_text_color    f{{theme.term.cursor_text_color}}

# black
color0               f{{theme.term.normal.black}}
color8               f{{theme.term.bright.black}}

# red
color1               f{{theme.term.normal.red}}
color9               f{{theme.term.bright.red}}

# green
color2               f{{theme.term.normal.green}}
color10              f{{theme.term.bright.green}}

# yellow
color3               f{{theme.term.normal.yellow}}
color11              f{{theme.term.bright.yellow}}

# blue
color4               f{{theme.term.normal.blue}}
color12              f{{theme.term.bright.blue}}

# purple (red)
color5               f{{theme.term.normal.purple}}
color13              f{{theme.term.bright.purple}}

# cyan (blue)
color6               f{{theme.term.normal.cyan}}
color14              f{{theme.term.bright.cyan}}

## white
color7               f{{theme.term.normal.white}}
color15              f{{theme.term.bright.white}}

and use symconf to dynamically fill these variables based on a selected biome/harshness/mode. This can be done for any app config file.