Themes

Kova ships with 11 built-in themes and supports fully custom themes via YAML files.

Selecting a theme

Open the Inspector panel (click ⓘ in the titlebar) and choose a theme from the swatches in the Theme section. The change is instant and Kova saves it to the file automatically.

Built-in themes

ID	Style
`light`	Clean white background, dark text — the default
`dark`	Deep charcoal background, light text
`institutional`	Formal navy and white with a structured header bar
`minimal`	No decorative elements; maximum focus on content
`editorial`	Serif typography, warm off-white — editorial / essay feel
`slate`	Dark blue-grey with accent highlights
`pitch`	High-contrast black with bold typographic hierarchy
`cosmos`	Deep space-inspired dark palette with indigo accents
`forge`	Industrial dark with amber highlights
`grove`	Earthy greens and warm neutrals
`horizon`	Gradient sunrise palette, soft and optimistic

Theme library

The More Themes… button in the Inspector links to themes.kova.md, where community-created themes are available to download. Downloads are verified against SHA-256 checksums.

Inspector overrides

Without writing a custom theme file, you can override specific aspects of any built-in theme from the Inspector:

Override	What it changes
Primary colour	Accent colour used for headings, progress bars, and decorative elements
Background colour	Slide background
Text colour	Body text
Heading colour	Content-slide heading colour; falls back to Text colour until set
Bold text colour	Inline bold/`<strong>` colour; falls back to Text colour until set
Title font	Font used for H1 and H2 headings
Body font	Font used for all other text
Code font	Monospace font for code blocks
Logo	Image displayed in the header or footer
Header text	Custom text shown at the top of every slide — supports template variables and `\\|` segmented layout
Header → Hide on title slide	Suppresses the header on the title slide only, keeping it everywhere else
Footer text	Custom text shown at the bottom — supports `{slide_number}`, `{total}`, `{title}`, `{author}`, `{date}` and `\\|` segmented layout
Footer → Hide on title slide	Suppresses the footer on the title slide only, keeping it everywhere else
Table of contents → Numbered list	Toggles a `!toc` slide between a numbered list and a plain hyperlinked list. On by default

Kova saves overrides to the file automatically. Logo, Header, Footer, and Table of Contents controls live together under the Inspector's Document section.

A small dot appears next to a control's label whenever its current value differs from the active theme's own default — i.e. it's been overridden via theme_overrides — as a quick visual sense of how much customising a document carries, which might be a sign it's worth promoting to a proper custom theme instead.

Heading and bold colour

Headings and bold/<strong> text can take a colour distinct from body text — set it via the Heading colour / Bold text colour swatches above, or directly in YAML via theme_overrides in a deck's frontmatter, or the heading/bold keys in a custom theme file:

theme_overrides:
  colors:
    heading: "#0057B8"
    bold:    "#B8003F"

Set heading/bold in a custom theme's colors block (see Color reference) to apply the colours to every document using that theme, rather than one document at a time via the Inspector.

Both colours fall back to the theme's plain text colour when unset, and both are still overridden by a slide's own per-slide text colour or invert directive, so a slide's text stays legible together rather than mixing an old heading colour with a new per-slide one.

Font availability

If a font you've chosen in the Inspector isn't installed on the current machine, a ⚠ warning appears next to the font name in the Inspector. Slides will fall back to the theme's default font until the missing font is installed.

Custom themes

Create a .yaml file in your custom themes folder to define a fully custom theme — see Settings & Keybindings — Themes for the exact path on each platform. Kova loads all valid .yaml files from that directory on startup, and watches the folder while running — adding, editing, or removing a .yaml/.yml file there (from any editor) reloads it automatically within moments, no restart needed. Any parse errors are reported in Settings → Themes.

File format

# my-brand.yaml, saved to your custom themes folder

name: My Brand          # Display name shown in the Inspector
id: my-brand            # The ID Kova uses internally to reference this theme
extends: light          # Optional — base theme for any field this file doesn't set. A built-in ID, or another installed custom theme's `id`. Defaults to `light`. See "Inheriting from other themes" below.

colors:
  primary:    "#0057B8"   # Background of title and section slides
  accent:     "#003F8A"   # Links, progress bars, and highlights
  background: "#FFFFFF"   # All other slide backgrounds
  text:       "#1A1A1A"   # Body text
  title_text: "#FFFFFF"   # Heading text on title and section slides
  section_bg: "#E8F0FE"   # Overrides primary for section slides only
  code_bg:    "#F3F4F6"   # Code block background
  heading:    "#0057B8"   # Content-slide heading colour (optional, falls back to `text`)
  bold:       "#B8003F"   # Inline **bold**/<strong> colour (optional, falls back to `text`)
  chart_colors:            # Optional palette override for pie/xychart/timeline diagrams
    - "#0057B8"
    - "#00A676"
    - "#F2A900"
  diagram_colors:          # Optional overrides for Mermaid flowchart/sequence colours — see "Diagram & chart colours" below
    primary: "#0057B8"
    border:  "#003F8A"
    line:    "#5C6773"
    cluster: "#E8F0FE"
    text:    "#1A1A1A"

fonts:
  title: "Georgia, serif"       # H1 and H2
  body:  "Inter, sans-serif"    # All other text
  code:  "JetBrains Mono, monospace"

layout:
  title_align:   center   # "center" | "left" | "bottom-left" — text alignment on title slide
  heading_align: left     # "left" | "center" — heading alignment on content slides
  decoration:    none     # "none" | "dots" | "grid" | "diagonal" | "bar-left"

logo: logo.png                      # Absolute path, https:// URL, data:image/... URI, or — as here — a path relative to this theme file's own directory
logo_position: bottom-left          # "top-left" | "top-right" | "bottom-left" | "bottom-right"

footer:
  show:              false
  text:              "{title} | {date} | {slide_number}/{total}"
  show_slide_number: true
  hide_on_title:     false   # true suppresses the footer on the title slide only, keeping it everywhere else

header:
  show: false
  text: ""
  hide_on_title: false   # true suppresses the header on the title slide only, keeping it everywhere else

toc:
  numbered: true   # false renders a plain hyperlinked list instead of a numbered one

Logo paths

logo accepts an absolute path, an https:// URL, or a data:image/... URI — or, as of the theme file's own directory being known, a path relative to the theme file itself (e.g. logo.png sitting next to theme.yaml), so a self-contained theme folder keeps working if it's moved or renamed. A relative path only resolves for a theme loaded from a file; it's dropped for a theme with no file backing it. On Windows, use forward slashes or a single backslash — do not quote the path or double-escape backslashes.

Color reference

Key	What it controls
`primary`	Background of title and section slides
`accent`	Links, progress bars, and highlight elements
`background`	Background of all other slides
`text`	Body text
`title_text`	Heading text on title and section slides — set this if `primary` is dark, otherwise text may be unreadable
`section_bg`	Background of section slides only; overrides `primary` for those slides
`code_bg`	Code block background
`heading`	Content-slide heading colour; falls back to `text` when unset. See Heading and bold colour
`bold`	Inline `bold`/`<strong>` colour; falls back to `text` when unset

Diagram & chart colours

Mermaid diagrams otherwise derive their colours from primary/accent/code_bg/text above. Two optional keys under colors override that for specific diagram types instead:

Key	Type	Controls
`chart_colors`	list of hex colours	Palette used for pie, xychart, and timeline diagrams
`diagram_colors`	map, see below	Flowchart and sequence-diagram colours

diagram_colors fields, all optional and independent:

Field	Controls
`primary`	Node/actor fill
`border`	Node/actor border; falls back to `primary` when unset
`line`	Connector lines
`cluster`	Subgraph/cluster background
`text`	Label text — doesn't affect pie-slice text, which stays tied to `title_text` for contrast on coloured slices

Both apply to the live preview and to PDF/PowerPoint export alike. There's no Inspector UI for either — set them via theme_overrides in a deck's frontmatter or a custom theme's colors block, the same as heading/bold colour above.

Template variables

Use these in header.text and footer.text:

Variable	Value
`{title}`	Document title
`{author}`	Document author (frontmatter `author:`)
`{date}`	Document date
`{slide_number}`	Current slide number
`{total}`	Total slide count

Segmented header/footer layout

Use | as a stretch separator to divide a header or footer into left, centre, and right sections:

header:
  show: true
  text: "My Deck | {title} | {date}"

footer:
  show: true
  text: "{title} | | {slide_number}/{total}"

Example	Result
`Left header`	Left-aligned (unchanged)
`{date} \\| caption \\| {total}`	Three parts: left · centre · right
`\\| caption`	Centre-aligned
`\\|\\| {slide_number}/{total}`	Right-aligned

Text without a | renders left-aligned as before, so existing decks are unaffected. Segmented layout works in both the Inspector text fields and custom theme YAML. It is also faithfully reproduced in PowerPoint export.

Inheriting from other themes

Omitted fields inherit from a base theme's defaults — the Light theme, unless you set extends:. You only need to specify what you want to change:

name: Dark Blue
id: dark-blue

colors:
  background: "#0D1117"
  text:       "#E6EDF3"
  primary:    "#58A6FF"

Set extends: <id> to inherit from a different theme instead of Light — any built-in ID (dark, slate, pitch, …) or another installed custom theme's own id:

name: Dark Blue Compact
id: dark-blue-compact
extends: dark-blue   # start from dark-blue above, only changing layout here

layout:
  heading_align: left

extends chains resolve transitively, so a custom theme can build on another custom theme that itself extends a third. If extends names a theme that doesn't exist, failed to parse, or forms a cycle (including extending itself), that entry falls back to the Light theme instead, with a warning shown in Settings → Themes — never the whole batch of custom themes failing together.

Applying changes

Edit the YAML file — no restart needed. Kova watches the custom themes folder while it's running and reloads a .yaml/.yml file within moments of it being added, changed, or removed, whether the edit comes from another editor or Kova's own theme tooling; any open document using that theme updates live. YAML syntax errors are shown in Settings → Themes with the file path and error detail.