InputHandler::prompt takes a color pair to use

README.asciidoc

@@ -411,6 +411,7 @@ there are some builtins color aliases:
  * +Error+: colors of error messages
  * +StatusLine+: colors used for the status line
  * +StatusCursor+: colors used for the status line cursor
+ * +Prompt+: colors used prompt displayed on the status line
 
 Shell expansion
 ---------------

src/color_registry.cc

@@ -52,6 +52,7 @@ ColorRegistry::ColorRegistry()
         { "Error", { Color::Black, Color::Red } },
         { "StatusLine", { Color::Cyan, Color::Default } },
         { "StatusCursor", { Color::Black, Color::Cyan } },
+        { "Prompt", { Color::Cyan, Color::Blue} },
       }
 {}
 

src/input_handler.cc

@@ -286,12 +286,12 @@ class Prompt : public InputMode
 {
 public:
     Prompt(InputHandler& input_handler, const String& prompt,
-           Completer completer, PromptCallback callback)
+           ColorPair colors, Completer completer, PromptCallback callback)
-        : InputMode(input_handler), m_prompt(prompt),
+        : InputMode(input_handler), m_prompt(prompt), m_prompt_colors(colors),
           m_completer(completer), m_callback(callback)
     {
         m_history_it = ms_history[m_prompt].end();
-        context().ui().print_status(line_with_cursor(m_prompt, m_prompt.char_length()));
+        display();
     }
 
     void on_key(const Key& key) override
@@ -429,15 +429,22 @@ public:
             m_current_completion = -1;
             m_line_editor.handle_key(key);
         }
-        auto curpos = m_prompt.char_length() + m_line_editor.cursor_pos();
+        display();
-        context().ui().print_status(line_with_cursor(m_prompt + line, curpos));
         m_callback(line, PromptEvent::Change, context());
     }
 
 private:
+    void display() const
+    {
+        auto display_line = line_with_cursor(m_line_editor.line(), m_line_editor.cursor_pos());
+        display_line.insert(display_line.begin(), { m_prompt, m_prompt_colors });
+        context().ui().print_status(display_line);
+    }
+
     PromptCallback m_callback;
     Completer      m_completer;
     const String   m_prompt;
+    ColorPair      m_prompt_colors;
     Completions    m_completions;
     int            m_current_completion = -1;
     String         m_prefix;
@@ -784,11 +791,12 @@ void InputHandler::repeat_last_insert()
     assert(dynamic_cast<InputModes::Normal*>(m_mode.get()) != nullptr);
 }
 
-void InputHandler::prompt(const String& prompt, Completer completer,
+void InputHandler::prompt(const String& prompt, ColorPair prompt_colors,
-                          PromptCallback callback)
+                          Completer completer, PromptCallback callback)
 {
     m_mode_trash.emplace_back(std::move(m_mode));
-    m_mode.reset(new InputModes::Prompt(*this, prompt, completer, callback));
+    m_mode.reset(new InputModes::Prompt(*this, prompt, prompt_colors,
+                                        completer, callback));
 }
 
 void InputHandler::menu(const memoryview<String>& choices,

src/input_handler.hh

@@ -47,8 +47,8 @@ public:
     // abort or validation with corresponding PromptEvent value
     // returns to normal mode after validation if callback does
     // not change the mode itself
-    void prompt(const String& prompt, Completer completer,
+    void prompt(const String& prompt, ColorPair prompt_colors,
-                PromptCallback callback);
+                Completer completer, PromptCallback callback);
 
     // enter menu mode, callback is called on each selection change,
     // abort or validation with corresponding MenuEvent value

src/main.cc

@@ -145,7 +145,8 @@ void do_swap_case(Context& context)
 void do_command(Context& context)
 {
     context.input_handler().prompt(
-        ":", std::bind(&CommandManager::complete, &CommandManager::instance(), _1, _2, _3),
+        ":", get_color("StatusLine"),
+        std::bind(&CommandManager::complete, &CommandManager::instance(), _1, _2, _3),
         [](const String& cmdline, PromptEvent event, Context& context) {
              if (event == PromptEvent::Validate)
                  CommandManager::instance().execute(cmdline, context);
@@ -154,7 +155,7 @@ void do_command(Context& context)
 
 void do_pipe(Context& context)
 {
-    context.input_handler().prompt("|", complete_nothing,
+    context.input_handler().prompt("|", get_color("StatusLine"), complete_nothing,
         [](const String& cmdline, PromptEvent event, Context& context)
         {
             if (event != PromptEvent::Validate)
@@ -174,7 +175,7 @@ template<SelectMode mode, bool forward>
 void do_search(Context& context)
 {
     SelectionList selections = context.editor().selections();
-    context.input_handler().prompt("/", complete_nothing,
+    context.input_handler().prompt("/", get_color("StatusLine"), complete_nothing,
         [selections](const String& str, PromptEvent event, Context& context) {
             try
             {
@@ -313,7 +314,7 @@ void do_paste(Context& context)
 
 void do_select_regex(Context& context)
 {
-    context.input_handler().prompt("select: ", complete_nothing,
+    context.input_handler().prompt("select: ", get_color("Prompt"), complete_nothing,
         [](const String& str, PromptEvent event, Context& context) {
             if (event == PromptEvent::Validate)
             {
@@ -330,7 +331,7 @@ void do_select_regex(Context& context)
 
 void do_split_regex(Context& context)
 {
-    context.input_handler().prompt("split: ", complete_nothing,
+    context.input_handler().prompt("split: ", get_color("Prompt"), complete_nothing,
         [](const String& str, PromptEvent event, Context& context) {
             if (event == PromptEvent::Validate)
             {
@@ -375,7 +376,7 @@ template<bool matching>
 void do_keep(Context& context)
 {
     constexpr const char* prompt = matching ? "keep matching: " : "keep not matching: ";
-    context.input_handler().prompt(prompt, complete_nothing,
+    context.input_handler().prompt(prompt, get_color("Prompt"), complete_nothing,
         [](const String& str, PromptEvent event, Context& context) {
             if (event == PromptEvent::Validate)
             {
@@ -484,7 +485,7 @@ void do_rotate_selections(Context& context)
     if (count == 0)
         count = 1;
     context.editor().rotate_selections(count);
-};
+}
 
 enum class SelectFlags
 {