@@ -8,6 +8,21 @@ [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+## [0.10.0] - 2026-04-18
+
+### Changed
+
+- **ANSI colour**: Changed from hex colour codes to ANSI terminal colours
+- Removed light/dark mode detection and adaptive colour logic
+- Changed "Adaptive Styling" to "ANSI Colours" in `README`
+
+### Removed
+
+- Removed `border_colour`, `header_colour`, `text_colour`, `quit_colour` from
+TOML configuration
+- `HasDarkBackground()` check and `lightDark()` helper function
+- All `#RRGGBB` colour codes (replaced with ANSI codes)
+
 ## [0.9.0] - 2026-04-17
 
 ### Added

@@ -12,7 +12,7 @@ - **Date-Based Progression**: Automatically calculates position based on day of
 year (1 January = Matthew 1:1-12)
 - **Smart Sizing**: Default snippet size is 12 verses, extends to end of
 chapter if less than 12 verses remain
-- **Adaptive Styling**: Terminal-adaptive colours and borders using `lipgloss`
+- **ANSI Colours: Uses ANSI terminal colours set by terminal emulator
 - **Interactive Controls**: Press `q` to quit (MOTD-like behaviour)
 - **Yearly Cycle**: Progresses through all four Gospels each year, restarting
 on 1 January
@@ -94,11 +94,6 @@ - **show_quit_message**: Whether to show "Press q to quit..." message (default:
 true)
 - **border_style**: Box border style: "rounded", "double", "single", or
 "hidden" (default: "rounded")
-- **border_colour**: Box border colour (hex or named colour, empty for
-adaptive)
-- **header_colour**: Header text colour (empty for adaptive)
-- **text_colour**: Bible text colour (empty for adaptive)
-- **quit_colour**: Quit message colour (empty for adaptive)
 
 #### Formatter Settings (`[formatter]` section)
 - **use_colours**: Whether to use ANSI colours in formatted output (default:
@@ -193,7 +188,7 @@
 ### Progress Bar Features
 - **Visual Progress**: Filled segments (█) showing annual cycle percentage between consecutive Easters
 - **Time Display**: Shows exact days, hours, and minutes until next Easter
-- **Styling**: Uses `lipgloss` with green-filled segments and adaptive terminal colours
+- **Styling: Uses `lipgloss` with ANSI-coloured segments
 - **Configuration**: Easter type configurable via `easter_type` field in TOML configuration
 
 ### Easter Calculations

@@ -18,13 +18,6 @@ show_quit_message = true
   
   # Box border style: "rounded", "double", "single", or "hidden"
   border_style = "rounded"
-  
-  # Colours for TUI elements (empty = adaptive to terminal)
-  # Use hex colours like "#FF0000" or named colours like "red"
-  border_colour = ""    # Box border colour
-  header_colour = ""    # Header text colour  
-  text_colour = ""      # Bible text colour
-  quit_colour = ""      # Quit message colour
 
 [formatter]
   # Whether to use ANSI colours in formatted output mode

@@ -55,18 +55,6 @@ ShowQuitMessage bool `toml:"show_quit_message" mapstructure:"show_quit_message"`
 
 		// Box border style: "rounded", "double", "single", "hidden"
 		BorderStyle string `toml:"border_style" mapstructure:"border_style"`
-
-		// Box border colour (default: adaptive to terminal)
-		BorderColour string `toml:"border_colour" mapstructure:"border_colour"`
-
-		// Header colour (default: adaptive to terminal)
-		HeaderColour string `toml:"header_colour" mapstructure:"header_colour"`
-
-		// Text colour (default: adaptive to terminal)
-		TextColour string `toml:"text_colour" mapstructure:"text_colour"`
-
-		// Quit message colour (default: adaptive to terminal)
-		QuitColour string `toml:"quit_colour" mapstructure:"quit_colour"`
 	} `toml:"tui" mapstructure:"tui"`
 
 	// Formatter settings
@@ -105,10 +93,6 @@ }
 
 	cfg.TUI.ShowQuitMessage = true
 	cfg.TUI.BorderStyle = "rounded"
-	cfg.TUI.BorderColour = "" // Empty means adaptive
-	cfg.TUI.HeaderColour = "" // Empty means adaptive
-	cfg.TUI.TextColour = ""   // Empty means adaptive
-	cfg.TUI.QuitColour = ""   // Empty means adaptive
 
 	cfg.Formatter.UseColours = true
 	cfg.Formatter.HeaderFormat = "{book} {chapter}\nw. {first_verse}-{second_verse}"
@@ -142,10 +126,6 @@ viper.SetDefault("bible_path", defaultCfg.BiblePath)
 	viper.SetDefault("easter_type", defaultCfg.EasterType)
 	viper.SetDefault("tui.show_quit_message", defaultCfg.TUI.ShowQuitMessage)
 	viper.SetDefault("tui.border_style", defaultCfg.TUI.BorderStyle)
-	viper.SetDefault("tui.border_colour", defaultCfg.TUI.BorderColour)
-	viper.SetDefault("tui.header_colour", defaultCfg.TUI.HeaderColour)
-	viper.SetDefault("tui.text_colour", defaultCfg.TUI.TextColour)
-	viper.SetDefault("tui.quit_colour", defaultCfg.TUI.QuitColour)
 	viper.SetDefault("formatter.use_colours", defaultCfg.Formatter.UseColours)
 	viper.SetDefault("formatter.header_format", defaultCfg.Formatter.HeaderFormat)
 	viper.SetDefault("formatter.numbered", defaultCfg.Formatter.Numbered)
@@ -219,10 +199,6 @@ viper.Set("bible_path", cfg.BiblePath)
 	viper.Set("easter_type", cfg.EasterType)
 	viper.Set("tui.show_quit_message", cfg.TUI.ShowQuitMessage)
 	viper.Set("tui.border_style", cfg.TUI.BorderStyle)
-	viper.Set("tui.border_colour", cfg.TUI.BorderColour)
-	viper.Set("tui.header_colour", cfg.TUI.HeaderColour)
-	viper.Set("tui.text_colour", cfg.TUI.TextColour)
-	viper.Set("tui.quit_colour", cfg.TUI.QuitColour)
 	viper.Set("formatter.use_colours", cfg.Formatter.UseColours)
 	viper.Set("formatter.header_format", cfg.Formatter.HeaderFormat)
 	viper.Set("formatter.numbered", cfg.Formatter.Numbered)

@@ -51,47 +51,18 @@ }
 
 // createStyles creates the lipgloss styles based on configuration
 func createStyles(config *bible.Config) *Styles {
-	// Detect if terminal has dark background
-	hasDarkBG := lipgloss.HasDarkBackground()
-
-	// Helper function for light/dark colors
-	lightDark := func(light, dark lipgloss.TerminalColor) lipgloss.TerminalColor {
-		if hasDarkBG {
-			return dark
-		}
-		return light
-	}
-
-	// Get colours from config, or use adaptive defaults
-	var borderColour, headerColour, textColour, quitColour lipgloss.TerminalColor
-
-	// Border colour
-	if config.TUI.BorderColour != "" {
-		borderColour = lipgloss.Color(config.TUI.BorderColour)
-	} else {
-		borderColour = lightDark(lipgloss.Color("#666666"), lipgloss.Color("#999999"))
-	}
-
-	// Header colour (matching formatter's green)
-	if config.TUI.HeaderColour != "" {
-		headerColour = lipgloss.Color(config.TUI.HeaderColour)
-	} else {
-		headerColour = lightDark(lipgloss.Color("#00AA00"), lipgloss.Color("#00FF00"))
-	}
-
-	// Text colour
-	if config.TUI.TextColour != "" {
-		textColour = lipgloss.Color(config.TUI.TextColour)
-	} else {
-		textColour = lightDark(lipgloss.Color("#000000"), lipgloss.Color("#FFFFFF"))
-	}
-
-	// Quit message colour
-	if config.TUI.QuitColour != "" {
-		quitColour = lipgloss.Color(config.TUI.QuitColour)
-	} else {
-		quitColour = lightDark(lipgloss.Color("#555555"), lipgloss.Color("#AAAAAA"))
-	}
+	// Use ANSI colours (set by terminal emulator)
+	// Border colour - bright black (gray)
+	borderColour := lipgloss.Color("8") // ANSI bright black (gray)
+	
+	// Header colour - green (matching formatter's green)
+	headerColour := lipgloss.Color("2") // ANSI green
+	
+	// Text colour - default terminal text colour
+	textColour := lipgloss.Color("") // Default terminal colour
+	
+	// Quit message colour - bright black (gray)
+	quitColour := lipgloss.Color("8") // ANSI bright black (gray)
 
 	// Create border style based on config
 	var border lipgloss.Border
@@ -124,7 +95,7 @@ content: lipgloss.NewStyle().
 			Foreground(textColour),
 
 		numberStyle: lipgloss.NewStyle().
-			Foreground(lightDark(lipgloss.Color("#444444"), lipgloss.Color("#AAAAAA"))).
+			Foreground(lipgloss.Color("8")). // ANSI bright black (gray)
 			Bold(false),
 
 		quitMessage: lipgloss.NewStyle().
@@ -250,7 +221,7 @@ progress, err := m.easterProg.GetEasterProgressPercentage()
 	if err != nil {
 		// If we can't calculate Easter, show error message
 		errorStyle := lipgloss.NewStyle().
-			Foreground(lipgloss.Color("#FF4444")).
+			Foreground(lipgloss.Color("1")). // ANSI red
 			Italic(true)
 		return errorStyle.Width(width - 6).Render("Unable to calculate Easter date")
 	}
@@ -272,14 +243,14 @@ // Calculate filled width
 	filledWidth := max(min(int(float64(barWidth)*progress), barWidth), 0)
 	emptyWidth := barWidth - filledWidth
 
-	// Define styles
+	// Define styles using ANSI colours
 	filledStyle := lipgloss.NewStyle().
-		Foreground(lipgloss.Color("#FFFFFF")).
-		Background(lipgloss.Color("#00AA00"))
+		Foreground(lipgloss.Color("15")). // Bright white
+		Background(lipgloss.Color("2"))   // Green
 
 	emptyStyle := lipgloss.NewStyle().
-		Foreground(lipgloss.Color("#888888")).
-		Background(lipgloss.Color("#222222"))
+		Foreground(lipgloss.Color("8")).  // Bright black (gray)
+		Background(lipgloss.Color("0"))   // Black
 
 	// Create bar segments
 	filledBar := filledStyle.Render(strings.Repeat("█", filledWidth))
@@ -289,14 +260,14 @@
 	// Add percentage text
 	percentage := fmt.Sprintf("%.1f%%", progress*100)
 	percentageStyle := lipgloss.NewStyle().
-		Foreground(lipgloss.Color("#AAAAAA")).
+		Foreground(lipgloss.Color("8")). // ANSI bright black (gray)
 		Bold(true)
 
 	percentageText := percentageStyle.Render(percentage)
 
 	// Combine time text, bar, and percentage
 	timeStyle := lipgloss.NewStyle().
-		Foreground(lipgloss.Color("#CCCCCC"))
+		Foreground(lipgloss.Color("7")) // ANSI white (light gray)
 
 	timeText := timeStyle.Width(barWidth - len(percentage) - 2).Render(timeStr)