05 — Theming

Set-UITheme applies colors/typography to the current canvas. Call it after New-PoshUICanvas and before (or interleaved with) adding controls.

Set-UITheme [-Theme <hashtable>] [-Light <hashtable>] [-Dark <hashtable>]
  [-Preset Dark|Light|Midnight|Slate]
  [-Accent Indigo|Emerald|Sky|Amber|Rose|Violet|Cyan|Orange]
  [-Mode Light|Dark|Auto]

One-call presets (recommended)

Set-UITheme -Preset Slate -Accent Sky        # a complete look in one line

• -Preset applies a curated full palette and sets the base mode:
  • Dark — deep indigo/navy (the default look).
  • Midnight — near-black blue.
  • Slate — slate gray-blue.
  • Light — light surfaces, dark text.
• -Accent recolors just the accent (buttons, highlights): Indigo|Emerald|Sky|Amber|Rose|Violet|Cyan|Orange.
• Compose order: preset → accent → explicit -Theme slots (explicit slots always win):

  Set-UITheme -Preset Slate -Accent Sky -Theme @{ CardBackground = '#10192E' }

Slot overrides (full control)

Pass a hashtable of slot = '#hex'. Recognized slots:

Slot	Themes
AccentColor	primary brand / buttons / highlights (also AccentLight, AccentDark)
Background	app/window background
ContentBackground	content area background
CardBackground	cards, chart cards
TitleBarBackground / TitleBarText	custom title bar
BorderColor	borders/dividers
TextPrimary	headings/body text
TextSecondary	muted/secondary text
ButtonBackground / ButtonForeground	standard buttons
InputBackground / InputBorder	text inputs
SidebarBackground / SidebarText / SidebarHighlight	nav rail
FontFamily	base font (non-color slot)

Set-UITheme @{
    AccentColor = '#6366F1'; Background = '#0A0E1A'; ContentBackground = '#0A0E1A'
    CardBackground = '#141A2E'; TitleBarBackground = '#0A0E1A'; BorderColor = '#243049'
    TextPrimary = '#E5E9F5'; TextSecondary = '#94A3B8'
}

Per-mode overrides

Provide light/dark variants; the active mode picks one:

Set-UITheme -Mode Auto -Light @{ Background = '#F4F6FB'; TextPrimary = '#1E2433' } `
                       -Dark  @{ Background = '#0A0E1A'; TextPrimary = '#E5E9F5' }

Notes

• Tooltips are themed app-wide automatically (dark card, not the white OS popup).
• All colors are hex (#RGB, #RRGGBB, or #AARRGGBB). Non-hex values for color slots are rejected with a warning.
• Set the title-bar slots if you customize the window chrome, or it may render with the default color.
• The demos typically pair a preset with a couple of explicit slots, e.g.:

  New-PoshUICanvas -Title 'App' -Theme Dark | Out-Null
  Set-UITheme -Preset Slate -Accent Sky | Out-Null