Themes

Built-in themes#

terminal-svg --list-themes prints the list your binary actually has. The palettes live in themes/, sourced from each scheme's official palette documentation. There's a rendered gallery of all of them at terminal-svg.dev.

Theme format#

A theme is a single TOML file. Pass it with -t:

terminal-svg -t path/to/my-theme.toml -- htop

Anything with a / in it or ending in .toml is treated as a file path; otherwise the name is looked up in the built-ins.

The auto theme#

asciinema 3 embeds the recording terminal's colours in the cast file (term.theme in the asciicast v3 header). -t auto renders with that palette, so the SVG looks like the terminal the session was recorded in:

asciinema rec demo.cast
terminal-svg demo.cast -t auto -o demo.svg

auto only works for cast inputs that carry a theme — v2 casts and other input modes error, since there's nothing to detect. The default stays dracula in all cases: output never changes palette based on the input file unless you ask. Window chrome colours (title text, buttons) are derived from the embedded foreground/background the same way they are for a TOML theme without a [chrome] section.

Full reference#

name = "my-theme"

[colors]                      # all 18 keys required, #rrggbb or #rgb
foreground = "#f8f8f2"        # default text colour
background = "#282a36"        # window body colour

black = "#21222c"             # ANSI 0-7
red = "#ff5555"
green = "#50fa7b"
yellow = "#f1fa8c"
blue = "#bd93f9"
magenta = "#ff79c6"
cyan = "#8be9fd"
white = "#f8f8f2"

bright_black = "#6272a4"      # ANSI 8-15
bright_red = "#ff6e6e"
bright_green = "#69ff94"
bright_yellow = "#ffffa5"
bright_blue = "#d6acff"
bright_magenta = "#ff92df"
bright_cyan = "#a4ffff"
bright_white = "#ffffff"

[chrome]                      # everything here is optional
title_fg = "#6272a4"          # default: foreground blended 45% toward background
shadow_opacity = 0.35         # default: 0.35 (github-light uses 0.25)
light_close = "#ff5f57"       # traffic light overrides; defaults are the
light_minimize = "#febc2e"    #   standard macOS red/amber/green
light_zoom = "#28c840"
button_fg = "#6272a4"         # caption glyphs (--chrome windows/ubuntu);
                              #   default: title_fg
button_bg = "#2f3240"         # button discs (--chrome ubuntu); default:
                              #   title_fg blended 85% toward background
bar_bg = "#ffffff"            # title bar fill (--chrome windows/ubuntu);
                              #   default: the authentic OS chrome color
bar_fg = "#000000"            # title/glyph color on that bar

What themes do and don't control#

• ANSI 0–15 come from the palette above.
• ANSI 16–231 (the 6×6×6 colour cube) and 232–255 (grayscale ramp) are computed from the xterm standard formula and are the same in every theme — this is what real terminals do.
• Truecolor (ESC[38;2;r;g;b m) passes straight through untouched.
• Faint text is the foreground blended 50% toward the effective background; inverse swaps foreground and background. Bold does not auto-brighten colours 0–7 (matching modern terminal defaults).

Contributing a built-in#

Add the TOML to themes/, register it in src/theme/builtin.rs, and check the name field matches the registry key (a test enforces this). Source palette values from the scheme's official palette documentation, not from screenshots.