theme

Theme module: restyle elements without touching them individually.

local theme = basalt.use("theme")
theme.set({ Button = { background = basalt.rgb("#89b4fa") } })
theme.apply(frame, { Label = { foreground = colors.yellow } })

theme.set() changes CLASS defaults: every element that never set the property explicitly follows immediately (including existing ones). theme.apply() assigns per element (explicit override) on a subtree. A states table defines property overrides while named states are active.

Values may be plain values or functions (dynamic values). Reactive "{...}" strings only work in apply(), not in set() — defaults are shared between elements, use a function instead.

Fields

Field	Type	Description
classes	table<string, table>	Element classes available to themes
presets	table<string, table>	Registered named theme presets

Methods

theme.set(themeTable)

Changes class-level defaults for the given element types.

• themeTable (table) Map of type name -> { property = value, states = {...} }

theme.set({ Button = { background = colors.blue } })

theme.applyPreset(presetOrName)

Applies a preset (by name or as a table from theme.load) via theme.set.

• presetOrName (string|table) Preset name or loaded preset table

• returns colors (table) The preset's color tokens

local pal = theme.applyPreset("basalt")

theme.load(path)

Loads a theme file and registers it as a preset. Returns (name, preset); pass the name straight into applyPreset: theme.applyPreset(theme.load("themes/obsidian.json")) .json files are parsed as JSON, everything else with textutils.unserialize.

• path (string) Path to the theme file

• returns name (string) The registered preset name

• returns preset (table) The resolved preset ({ colors, styles })

theme.apply(root, themeTable)

Applies properties to every matching element in a subtree (by type name).

• root (Element) Root element
• themeTable (table) Map of class names to properties/state styles