# 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 _four_ monotone bases and _five_ accent colors. 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 four can be selected to change the feeling of the palette without sacrificing
readability.

![Theme preview](images/repo_preview.png)
_(Preview of default light and dark theme variants)_

See screenshots for the full set of theme variants in [THEMES](THEMES.md) (also discussed
below).

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

- `mono-`: `monobiome` is inspired by the [`monoindustrial` theme][1], 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 consists of four monotone bases and five accent colors, each of
which is anchored by hue and spread uniformly across lightness levels 15 to 95 (in OKLCH
space). 

![Diagram of palette accents and monotones](images/palette.png)

The chroma curve for each accent is carefully designed to vary smoothly across the
lightness spectrum, with the goal of retaining strong color identity in all settings.
Additionally, as alluded to above, the (WCAG 2) contrast ratio between any choice of
monotone background at a given lightness level and the accent colors is virtually
identical ($\pm 0.1$). Put another way, the relative contrast between accents depends only
on the _lightness_ of the background monotone, not its hue.

## Concrete themes
![Light biomes](images/light_code_caps.png)
_(Default light theme variants)_

![Dark biomes](images/dark_code_caps.png)
_(Default dark theme variants)_

Themes are derived from the `monobiome` palette by varying both the monotone hue (the
"biome") and the extent of the background/foreground lightness (the "harshness"). This is
done for both light and dark schemes, and in each case accent colors are selected at a
lightness level that ensures each meet a minimum contrast relative to the primary
background. The following diagram shows each of the 24 resulting combinations:

![Diagram of the 24 available concrete theme options](images/themes.png)

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. For example, the following demonstrates how background and
foreground elements are chosen for the `monobiome` Vim themes:

![
  Diagram depicting how themes colors are selected by harshness and mapped onto
  application-specific elements
](images/vim_theme_elements.png)

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 `grey` 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 of the 24 theme options can applied immediately.

Read more about how themes are created in [DESIGN](DESIGN.md).

# Usage
This repo provides the 24 theme files for `kitty`, `vim`/`neovim`, [`vim-airline`][2], and
`fzf` in the `apps/` directory. You can also find raw palette colors in
`colors/monobiome.toml` if you want to use them to define themes for other applications.

Each of the files in the `apps/` directory are named according to

```sh
<harshness>-<biome>-monobiome-<mode>.<config>
```

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

## `kitty`
Find `kitty` themes in `apps/kitty`. Themes can be activated in your `kitty.conf` with

```sh
include <theme-file>
```

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

```sh
colorscheme <theme-name>
```

## `vim-airline`
If you use [`vim-airline`][2], you can find statusline themes in `apps/vim-airline`.
Place a theme file in the `airline` theme folder, and activate it in
your `.vimrc`/`init.vim` with

```sh
let g:airline_theme='<theme-name>'
```

## `fzf`
In `apps/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:

```sh
source <theme-file>
```

# Switching themes
[`symconf`][3] 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 `apps/symconf` 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

```conf
# 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.


[1]: https://github.com/isa/TextMate-Themes/blob/master/monoindustrial.tmTheme
[2]: https://github.com/vim-airline/vim-airline
[3]: https://github.com/ologio/symconf