Custom themes

Create a theme

Open Cressida > Themes in settings and copy the starter TOML.
Create the themes directory if it does not exist:
Terminal window
```
mkdir -p "${XDG_CONFIG_HOME:-$HOME/.config}/cressida/themes"
```
Save your theme there as my-theme.toml.
Return to the Themes page and select it.

Cressida watches the directory and reloads valid changes while it runs. You do not need to restart after editing colors.

Complete starter

Every theme needs both [dark] and [light], with all eight required colors in each. Color values must be quoted six-digit hex strings.

version = 1
name = "My theme"
description = "A soft violet palette."
author = "Your name"

[dark]
background = "#17181d"
sidebar = "#1e2027"
panel = "#24262f"
raised = "#2e313d"
foreground = "#eeeff5"
muted = "#989bae"
accent = "#c6b5f5"
ink = "#211a36"

[light]
background = "#f5f5f7"
sidebar = "#e8e9ee"
panel = "#dcdee6"
raised = "#cdd0dc"
foreground = "#20222c"
muted = "#616678"
accent = "#6d4db5"
ink = "#ffffff"

Color reference

Required color	Used for
`background`	Main background surfaces.
`sidebar`	Sidebar surfaces.
`panel`	Panel and control surfaces.
`raised`	Raised or hovered surfaces.
`foreground`	Main text.
`muted`	Secondary text.
`accent`	Accent controls and highlights.
`ink`	Text drawn on an accent fill.

Optional colors, inside either variant:

Keys	Purpose
`rail`	Server rail background.
`danger`, `destructive`, `success`	Status and action colors.
`keyword`, `string`, `number`, `function`, `type`, `property`, `preprocessor`	Syntax palette.
`added`, `removed`	Added and removed content.

Omitted optional colors use Cressida's fallback values. Check text against every surface it appears on, especially ink against accent, in both variants.

Names, limits and overrides

The filename without .toml is the palette ID. It must contain only lowercase letters, digits, hyphens and underscores, with at most 64 characters. name is the label shown in settings. description and author are optional.

Files must fit within 64 KiB; keep at most 256 themes in a directory. Unknown keys, invalid colors, missing variants or missing required fields reject the whole file. If an edit is incomplete or invalid, Cressida keeps the last valid version and shows an error on the Themes page.

A custom file with the same ID as a bundled palette overrides it. Removing the file restores the bundled palette or default fallback. Cressida remembers the selected ID so the custom theme can return when you restore its file.

Themes are ordinary user-owned files. For backup locations, see Files and data.