# TUI themes: how SeaShell looks in your terminal

> SeaShell ships a TUI theme system with a charcoal and blue default theme plus a set of presets you can switch between.

SeaShell ships a theme system for its terminal interface. The default is charcoal and blue, built around a near-black background and a blue accent, and a set of presets is included for people who already have a palette they read comfortably. Since a coding agent is something you look at for hours, this is 1 of the settings worth spending a minute on.

## Key takeaways

- The default theme is charcoal with a blue accent, tuned for long sessions.
- Presets are included for people who already have a preferred palette.
- Themes are data, not code, so a palette is a small file.
- SeaShell renders as a full terminal UI rather than scrolling log output.

## The default, and why it is dark and low contrast

SeaShell defaults to a near-black charcoal background with a blue accent rather than pure black on white. Over a 3-hour session, maximum contrast is the thing people stop tolerating first, and an agent's output is dense enough to make that worse.

The palette also has to do a job beyond comfort. Diffs, permission prompts, plans, and tool output all need to be distinguishable at a glance, so the accent colors are chosen for separation between states rather than for how a single screenshot looks. Reading a diff quickly is the actual design constraint.

## Presets and matching what you already use

SeaShell includes a set of preset themes, so a terminal already configured around 1 palette does not have to host an agent that fights it. Switching is a setting rather than a rebuild.

Consistency matters more than any individual palette being correct. If your terminal, editor, and agent disagree about what a warning color is, you spend attention translating between them. Matching the environment you already read is usually a better outcome than picking the objectively nicest theme.

## Themes are data

A theme is a small file of color definitions, not compiled code. The default declares its background and accent values directly, which means adjusting 1 color is an edit rather than a build step.

Keeping themes as data is what makes them practical to share. A palette that matches a company's terminal setup can be dropped in and passed around, and comparing two themes is comparing two short files rather than reading rendering logic. It also keeps the theme system from becoming a place where behavior accidentally lives.

## FAQ

### Can I change how SeaShell looks in the terminal?

Yes. SeaShell ships a TUI theme system with a charcoal and blue default theme plus a set of presets you can switch between.

### What is the default SeaShell theme?

A near-black charcoal background with a blue accent, chosen for readability over long sessions rather than maximum contrast.

### Can I make my own theme?

Yes. A theme is a small file of color definitions rather than code, so a custom palette is an edit and can be shared.

### Does SeaShell run as a full terminal UI?

Yes. SeaShell renders a full terminal interface rather than printing scrolling log output, which is what makes theming meaningful.

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Canonical HTML: https://seashell.sh/resources/features/tui-themes
Source of truth: aeo_pages row `/resources/features/tui-themes` (segment: Platform) (this file is generated from it, never hand-edited).
Licence: SeaShell is proprietary with a free core. It is not open source and there is no public source repository.