Styling & Themes

Tachikoma provides a comprehensive styling system with ANSI 256 colors, true RGB colors, text attributes, and a theme engine with 11 built-in palettes.

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

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 11 built-in 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

Theme API

theme()                    # get current Theme
set_theme!(KANEDA)         # set by Theme value
set_theme!(:kaneda)        # set by Symbol name
ALL_THEMES                 # tuple of all 11 themes

Theme changes take effect immediately — the next view call uses the new colors.

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]
to_rgb(c::Color256) → ColorRGB              # convert palette → RGB
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

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 = ['⣾','⣽','⣻','⢿','⡿','⣟','⣯','⣷']