Themes

A theme is a JSON file that sets ulo's colors. Put it at ~/.ulo/themes/<name>.json, or at themes/<name>.json in an installed package.

The names in /settings → Theme come from these directories plus the two built-ins, dark and light. A file named like a built-in replaces it. When both the home and a package have one, the home's file comes first.

On this page

Format

JSON

{
  "name": "mytheme",
  "vars": { "ink": 255, "dim": 245, "divider": 240, "shell": 71, "...": 0 },
  "colors": { "userMessageText": "ink", "border": "divider", "bashMode": "shell", "...": "" }
}

vars maps a palette name to a 256-color index or a "#RRGGBB" color.
colors maps a UI token to a var name, an index, or a hex color. "" means the terminal default.

To start, copy a built-in. ulo docs theme-dark prints the dark theme's JSON verbatim. Save it under a new name and edit it.

Apply a theme instantly with /reload, or pick it in /settings.

Tokens

These are the tokens you will most likely touch:

userMessageText, for the composer rail and user text
dim
border, for dividers
muted
bashMode, for the ! shell marker
accent
the syntax* family, for code tinting

ulo ignores unknown tokens. A missing token falls back to the terminal default, so a partial theme is valid.

Full transcript reader

The reader rails tool details with a │ in the muted tone, and shows output text dim. Its footer uses userMessageText for ┃ and muted for navigation.

Diff markers

Edit and write summary counts use these tokens. They also color the review's diff markers.

Terminal	Additions	Deletions
Truecolor	`toolDiffAddedMarker`	`toolDiffRemovedMarker`
Other	`toolDiffAddedMarkerFallback`	`toolDiffRemovedMarkerFallback`

By default additions are green and deletions are red. Labels and tree rails stay neutral.