Styling & Themes

Tachikoma provides a comprehensive styling system with ANSI 256 colors, true RGB colors, text attributes, and a theme engine with 24 built-in palettes across dark and light modes.

Style

Style controls how text and backgrounds appear:

Style(; fg=NoColor(), bg=NoColor(), bold=false, dim=false,
        italic=false, underline=false)

# Explicit style
s = Style(fg=Color256(196), bg=Color256(0), bold=false, italic=true)

# Theme-aware style (preferred)
s = tstyle(:primary, bold=true)

Color Types

Color256

ANSI 256-color palette (0–255):

Color256(196)     # bright red
Color256(46)      # green
Color256(0)       # black
Color256(255)     # white

ColorRGB

True 24-bit RGB color:

ColorRGB(255, 100, 50)   # orange
ColorRGB(0x1a, 0x1b, 0x2e)  # dark blue

ColorRGBA

A 4-byte pixel color with red, green, blue, and alpha channels (each a UInt8). Used internally by PixelImage, PixelCanvas, and the raw RGBA rendering pipeline — not a subtype of AbstractColor and cannot be used in Style for terminal text.

ColorRGBA(255, 0, 0)        # opaque red  (alpha defaults to 0xff)
ColorRGBA(255, 0, 0, 128)   # semi-transparent red
ColorRGBA(c::ColorRGB)      # promote ColorRGB → ColorRGBA (opaque)
ColorRGB(c::ColorRGBA)      # drop alpha channel → ColorRGB

Predefined constants:

BLACK       # ColorRGBA(0x00, 0x00, 0x00, 0xff)  — opaque black
TRANSPARENT # ColorRGBA(0x00, 0x00, 0x00, 0x00)  — fully transparent

NoColor

Transparent / terminal default:

NoColor()   # inherits terminal default

Theme-Aware Styles with tstyle

The tstyle function creates styles from the current theme's color fields:

tstyle(:primary)                  # theme's primary color as fg
tstyle(:primary, bold=true)       # primary fg, bold
tstyle(:accent, dim=true)         # accent fg, dimmed
tstyle(:error, underline=true)    # error fg, underlined

Available theme fields:

Field	Usage
:border	Normal border color
:border_focus	Focused border color
:text	Standard text
:text_dim	Subdued text
:text_bright	Emphasized text
:primary	Primary accent
:secondary	Secondary accent
:accent	Highlight / interactive elements
:success	Success indicators
:warning	Warning indicators
:error	Error indicators
:title	Title text

Always prefer tstyle over hardcoded colors — your app automatically adapts when the user switches themes.

Themes

Tachikoma ships with 24 built-in themes split into dark and light packs. Use *Ctrl+* to open the theme selector and Tab to switch between dark and light mode. Your choice is saved via Preferences.jl.

Dark Themes

Theme	Constant	Description
Kokaku	KOKAKU	Deep teal cyberpunk (default)
Esper	ESPER	Cool blue noir
Motoko	MOTOKO	Warm purple cyborg
Kaneda	KANEDA	Hot red/orange Neo-Tokyo
Neuromancer	NEUROMANCER	Green-on-dark hacker
Catppuccin	CATPPUCCIN	Warm pastel
Solarized	SOLARIZED	Ethan Schoonover's palette
Dracula	DRACULA	Dark purple classic
Outrun	OUTRUN	Neon synthwave
Zenburn	ZENBURN	Low-contrast warm
Iceberg	ICEBERG	Cool blue minimal

Light Themes

Theme	Constant	Description
Paper	PAPER	Clean minimal, black ink on white
Latte	LATTE	Catppuccin Latte, soft pastels on cream
Solaris	SOLARIS	Solarized Light, precision color science
Sakura	SAKURA	Cherry blossom pink on snow
Ayu	AYU	Warm daylight, ochre accents
Gruvbox	GRUVBOX	Retro groove, warm contrast on tan
Frost	FROST	Arctic clarity, ice blue on snow
Meadow	MEADOW	Natural greens on warm white
Dune	DUNE	Desert sand, warm earth tones
Lavender	LAVENDER	Soft purple haze on cool white
Horizon	HORIZON	Coastal sunrise, warm amber
Overcast	OVERCAST	Balanced mid-gray, works anywhere
Dusk	DUSK	Twilight gray, warm mids with cool accents

Theme API

theme()                    # get current Theme
set_theme!(KANEDA)         # set by Theme value
set_theme!(:kaneda)        # set by Symbol name
light_mode()               # true if light mode is active
set_light_mode!(true)      # switch to light mode
active_themes()            # themes for current mode
DARK_THEMES                # tuple of all dark themes
LIGHT_THEMES               # tuple of all light themes
ALL_THEMES                 # tuple of all themes (dark + light)

Theme changes take effect immediately — the next view call uses the new colors. Pixel canvases automatically use a white or black background to match the active mode.

ANSI Parsing Default

Strings passed to Paragraph and ScrollPane are automatically parsed for ANSI escape sequences (colors, bold, italic, etc.). Control this globally:

ansi_enabled()              # true by default
set_ansi_enabled!(false)    # disable globally

Per-widget ansi=true or ansi=false overrides the global default. See Paragraph and ScrollPane for details.

Theme Struct

Each Theme contains:

struct Theme
    name::String
    border::Color256
    border_focus::Color256
    text::Color256
    text_dim::Color256
    text_bright::Color256
    primary::Color256
    secondary::Color256
    accent::Color256
    success::Color256
    warning::Color256
    error::Color256
    title::Color256
end

Color Utilities

Interpolation and Manipulation

color_lerp(a::ColorRGB, b::ColorRGB, t)    # interpolate, t ∈ [0,1]
color_lerp(a::ColorRGBA, b::ColorRGBA, t)  # interpolate with alpha
brighten(c::ColorRGB, amount) → ColorRGB    # brighten by 0–1
dim_color(c::ColorRGB, amount) → ColorRGB   # dim by 0–1
hue_shift(c::ColorRGB, degrees) → ColorRGB  # rotate hue
desaturate(c::ColorRGB, amount) → ColorRGB  # reduce saturation

Color Conversion

to_rgb(c::Color256) → ColorRGB    # ANSI palette → 24-bit RGB
to_rgb(c::ColorRGBA) → ColorRGB   # drop alpha channel
to_rgba(c::ColorRGB) → ColorRGBA  # promote to RGBA (opaque)
to_rgba(c::ColorRGBA) → ColorRGBA # identity

# Requires ColorTypes.jl (loaded via TachikomaColorTypesExt):
to_colortype(c::ColorRGB)  → RGB{N0f8}   # Tachikoma → ColorTypes
to_colortype(c::ColorRGBA) → RGBA{N0f8}  # Tachikoma → ColorTypes
to_rgb(c::RGB{N0f8})       → ColorRGB    # ColorTypes → Tachikoma
to_rgba(c::RGBA{N0f8})     → ColorRGBA   # ColorTypes → Tachikoma

TachikomaColorTypesExt is a package extension that activates automatically when ColorTypes (or a package that re-exports it, such as Colors.jl or Makie) is loaded alongside Tachikoma. It provides two-way conversion between Tachikoma color types and the ColorTypes.jl ecosystem.

Animated Color

# Smooth color cycling (see Animation section)
color_wave(tick, x, colors; speed=0.04, spread=0.08) → ColorRGB

Render Backends

Tachikoma supports three rendering backends that affect how canvases and visual effects are drawn:

@enum RenderBackend braille_backend block_backend sixel_backend

render_backend()                    # get current
set_render_backend!(braille_backend)  # set + save
cycle_render_backend!(1)            # cycle forward
cycle_render_backend!(-1)           # cycle backward

Backend	Resolution	Description
braille_backend	2×4 per cell	Unicode braille dots, works everywhere
block_backend	2×2 per cell	Quadrant block characters, gap-free
sixel_backend	~16×32 per cell	Pixel-perfect raster, Kitty or sixel

Decay Parameters

The decay system adds a "bit-rot" aesthetic — noise, jitter, and corruption effects:

mutable struct DecayParams
    decay::Float64        # 0–1 master intensity
    jitter::Float64       # 0–1 RGB noise
    rot_prob::Float64     # 0–1 corruption probability
    noise_scale::Float64  # spatial noise scale
end

decay_params() → DecayParams   # get current (mutable)

Adjust via the settings overlay (Ctrl+S) or programmatically. Values are saved via Preferences.jl.

Box Styles

Four border box styles for Block:

BOX_ROUNDED    # ╭─╮╰─╯  (default)
BOX_HEAVY      # ┏━┓┗━┛
BOX_DOUBLE     # ╔═╗╚═╝
BOX_PLAIN      # ┌─┐└─┘

Block(title="Panel", box=BOX_HEAVY)

Visual Constants

DOT = '·'                              # separator dot
BARS_V = ('▁','▂','▃','▄','▅','▆','▇','█')  # vertical bar chars
BARS_H = ('▏','▎','▍','▌','▋','▊','▉','█')  # horizontal bar chars
BLOCKS = ('█','▓','▒','░')             # density blocks
SCANLINE = '╌'                         # interlace separator
MARKER = '▸'                           # list selection marker
SPINNER_BRAILLE = ['⠋','⠙','⠹','⠸','⠼','⠴','⠦','⠧','⠇','⠏']
SPINNER_DOTS = ['⣾','⣽','⣻','⢿','⡿','⣟','⣯','⣷']