macos: add `colorize_tab:<color>` binding

Resolves #11085

include/ghostty.h

@@ -760,6 +760,7 @@ typedef enum {
   GHOSTTY_ACTION_COLOR_KIND_FOREGROUND = -1,
   GHOSTTY_ACTION_COLOR_KIND_BACKGROUND = -2,
   GHOSTTY_ACTION_COLOR_KIND_CURSOR = -3,
+  GHOSTTY_ACTION_COLOR_KIND_TAB = -4,
 } ghostty_action_color_kind_e;
 
 // apprt.action.ColorChange

macos/Sources/Features/Command Palette/TerminalCommandPalette.swift

@@ -140,7 +140,6 @@ struct TerminalCommandPaletteView: View {
             guard let window = controller.window else { return [] }
 
             let color = (window as? TerminalWindow)?.tabColor
-            let displayColor = color != TerminalTabColor.none ? color : nil
 
             return controller.surfaceTree.map { surface in
                 let terminalTitle = surface.title.isEmpty ? window.title : surface.title
@@ -163,7 +162,7 @@ struct TerminalCommandPaletteView: View {
                     title: "Focus: \(displayTitle)",
                     subtitle: subtitle,
                     leadingIcon: "rectangle.on.rectangle",
-                    leadingColor: displayColor?.displayColor.map { Color($0) },
+                    leadingColor: color?.color.map { Color($0) },
                     sortKey: AnySortKey(ObjectIdentifier(surface))
                 ) {
                     NotificationCenter.default.post(

macos/Sources/Features/Terminal/TerminalTabColor.swift

@@ -1,7 +1,7 @@
 import AppKit
 import SwiftUI
 
-enum TerminalTabColor: Int, CaseIterable, Codable {
+enum TerminalTabColorPreset: Int, CaseIterable, Codable {
     case none
     case blue
     case purple
@@ -67,6 +67,8 @@ enum TerminalTabColor: Int, CaseIterable, Codable {
         }
     }
 
+    var tabColor: TerminalTabColor { TerminalTabColor(color: displayColor) }
+
     func swatchImage(selected: Bool) -> NSImage {
         let size = NSSize(width: 18, height: 18)
         return NSImage(size: size, flipped: false) { rect in
@@ -105,15 +107,57 @@ enum TerminalTabColor: Int, CaseIterable, Codable {
     }
 }
 
+struct TerminalTabColor: Equatable, Codable {
+    let color: NSColor?
+
+    static let none = TerminalTabColor(color: nil)
+
+    init(color: NSColor?) {
+        self.color = color
+    }
+
+    init(color: Color) {
+        self.color = NSColor(color)
+    }
+
+    // MARK: Codable
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        // Backward compatibility: attempt to decode the previously stored preset index.
+        if let preset = try? container.decode(TerminalTabColorPreset.self) {
+            self.color = preset.displayColor
+            return
+        }
+        let hex = try container.decode(String.self)
+        self.color = NSColor(hex: hex)
+    }
+
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(color?.hexString ?? "")
+    }
+
+    // MARK: Equatable
+
+    static func == (lhs: TerminalTabColor, rhs: TerminalTabColor) -> Bool {
+        lhs.color == rhs.color
+    }
+
+    var matchingPreset: TerminalTabColorPreset {
+        TerminalTabColorPreset.allCases.first { $0.displayColor == color } ?? .none
+    }
+}
+
 // MARK: - Menu View
 
 /// A SwiftUI view displaying a color palette for tab color selection.
 /// Used as a custom view inside an NSMenuItem in the tab context menu.
 struct TabColorMenuView: View {
-    @State private var currentSelection: TerminalTabColor
-    let onSelect: (TerminalTabColor) -> Void
+    @State private var currentSelection: TerminalTabColorPreset
+    let onSelect: (TerminalTabColorPreset) -> Void
 
-    init(selectedColor: TerminalTabColor, onSelect: @escaping (TerminalTabColor) -> Void) {
+    init(selectedColor: TerminalTabColorPreset, onSelect: @escaping (TerminalTabColorPreset) -> Void) {
         self._currentSelection = State(initialValue: selectedColor)
         self.onSelect = onSelect
     }
@@ -143,7 +187,7 @@ struct TabColorMenuView: View {
         .padding(.bottom, 4)
     }
 
-    static let paletteRows: [[TerminalTabColor]] = [
+    static let paletteRows: [[TerminalTabColorPreset]] = [
         [.none, .blue, .purple, .pink, .red],
         [.orange, .yellow, .green, .teal, .graphite],
     ]
@@ -161,7 +205,7 @@ struct TabColorMenuView: View {
 
 /// A single color swatch button in the tab color palette.
 private struct TabColorSwatch: View {
-    let color: TerminalTabColor
+    let color: TerminalTabColorPreset
     let isSelected: Bool
     let action: () -> Void
 

macos/Sources/Features/Terminal/Window Styles/TerminalWindow.swift

@@ -682,7 +682,7 @@ private struct TabColorIndicatorView: View {
     let tabColor: TerminalTabColor
 
     var body: some View {
-        if let color = tabColor.displayColor {
+        if let color = tabColor.color {
             Circle()
                 .fill(Color(color))
                 .frame(width: 6, height: 6)
@@ -773,17 +773,17 @@ extension TerminalWindow {
         let paletteItem = NSMenuItem()
         paletteItem.identifier = Self.tabColorPaletteIdentifier
         paletteItem.view = makeTabColorPaletteView(
-            selectedColor: (target?.window as? TerminalWindow)?.tabColor ?? .none
+            selectedColor: (target?.window as? TerminalWindow)?.tabColor.matchingPreset ?? .none
         ) { [weak target] color in
-            (target?.window as? TerminalWindow)?.tabColor = color
+            (target?.window as? TerminalWindow)?.tabColor = color.tabColor
         }
         menu.addItem(paletteItem)
     }
 }
 
 private func makeTabColorPaletteView(
-    selectedColor: TerminalTabColor,
-    selectionHandler: @escaping (TerminalTabColor) -> Void
+    selectedColor: TerminalTabColorPreset,
+    selectionHandler: @escaping (TerminalTabColorPreset) -> Void
 ) -> NSView {
     let hostingView = NSHostingView(rootView: TabColorMenuView(
         selectedColor: selectedColor,

macos/Sources/Ghostty/Ghostty.Action.swift

@@ -14,6 +14,7 @@ extension Ghostty.Action {
             case foreground
             case background
             case cursor
+            case tab
             case palette(index: UInt8)
         }
 
@@ -25,6 +26,8 @@ extension Ghostty.Action {
                 self.kind = .background
             case GHOSTTY_ACTION_COLOR_KIND_CURSOR:
                 self.kind = .cursor
+            case GHOSTTY_ACTION_COLOR_KIND_TAB:
+                self.kind = .tab
             default:
                 self.kind = .palette(index: UInt8(c.kind.rawValue))
             }

macos/Sources/Ghostty/Surface View/SurfaceView_AppKit.swift

@@ -764,6 +764,11 @@ extension Ghostty {
                     self?.backgroundColor = change.color
                 }
 
+            case .tab:
+                DispatchQueue.main.async { [weak self] in
+                    (self?.window as? TerminalWindow)?.tabColor = TerminalTabColor(color: change.color)
+                }
+
             default:
                 // We don't do anything for the other colors yet.
                 break

src/Surface.zig

@@ -5915,6 +5915,16 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
             .io => self.queueIo(.{ .crash = {} }, .unlocked),
         },
 
+        .colorize_tab => |hex| {
+            const color = try terminal.color.RGB.parse(hex);
+            return try self.rt_app.performAction(.{ .surface = self }, .color_change, .{
+                .kind = .tab,
+                .r = color.r,
+                .g = color.g,
+                .b = color.b,
+            });
+        },
+
         .adjust_selection => |direction| {
             self.renderer_state.mutex.lock();
             defer self.renderer_state.mutex.unlock();

src/apprt/action.zig

@@ -845,6 +845,7 @@ pub const ColorKind = enum(c_int) {
     foreground = -1,
     background = -2,
     cursor = -3,
+    tab = -4,
 
     // 0+ values indicate a palette index
     _,

src/input/Binding.zig

@@ -934,6 +934,29 @@ pub const Action = union(enum) {
     ///
     crash: CrashThread,
 
+    /// Mark the current tab with the color defined.
+    /// This is equivalent to right-click a tab and selecting one of the predefine color.
+    ///
+    /// For example, `colorize_tab:#632CA6`
+    ///
+    /// Any of the following forms are accepted:
+    ///
+    ///  - rgb:<red>/<green>/<blue>
+    ///    <red>, <green>, <blue> := h | hh | hhh | hhhh
+    ///    where `h` is a single hexadecimal digit.
+    ///
+    ///  - rgbi:<red>/<green>/<blue>
+    ///    where <red>, <green>, and <blue> are floating point values between
+    ///    0.0 and 1.0 (inclusive).
+    ///
+    ///  - #rgb, #rrggbb, #rrrgggbbb #rrrrggggbbbb
+    ///    where `r`, `g`, and `b` are a single hexadecimal digit.
+    ///    These specify a color with 4, 8, 12, and 16 bits of precision
+    ///    per color channel.
+    ///
+    /// Only implemented on macOS.
+    colorize_tab: []const u8,
+
     pub const Key = @typeInfo(Action).@"union".tag_type.?;
 
     /// Make this a valid gobject if we're in a GTK environment.
@@ -1391,6 +1414,7 @@ pub const Action = union(enum) {
             .resize_split,
             .equalize_splits,
             .inspector,
+            .colorize_tab,
             => .surface,
         };
     }

src/input/command.zig

@@ -706,6 +706,7 @@ fn actionCommands(action: Action.Key) []const Command {
         .deactivate_all_key_tables,
         .end_key_sequence,
         .crash,
+        .colorize_tab,
         => comptime &.{},
 
         // No commands because I'm not sure they make sense in a command