diff --git a/include/spdlog/sinks/ansicolor_sink.h b/include/spdlog/sinks/ansicolor_sink.h
index 3563e7b6..905d270a 100644
--- a/include/spdlog/sinks/ansicolor_sink.h
+++ b/include/spdlog/sinks/ansicolor_sink.h
@@ -38,7 +38,7 @@ public:
         , mutex_(ConsoleMutex::mutex())
 
     {
-        set_color_mode(mode);
+        set_color_mode_(mode);
         colors_[level::trace] = white;
         colors_[level::debug] = cyan;
         colors_[level::info] = green;
@@ -139,22 +139,28 @@ public:
     }
 
     void set_color_mode(color_mode mode)
+    {
+        std::lock_guard<mutex_t> lock(mutex_);
+        set_color_mode_(mode);
+    }
+
+private:
+    void set_color_mode_(color_mode mode)
     {
         switch (mode)
         {
         case color_mode::always:
             should_do_colors_ = true;
-            return;
+            break;
         case color_mode::automatic:
             should_do_colors_ = details::os::in_terminal(target_file_) && details::os::is_color_terminal();
-            return;
+            break;
         case color_mode::never:
             should_do_colors_ = false;
-            return;
+            break;
         }
     }
 
-private:
     void print_ccode_(const std::string &color_code)
     {
         fwrite(color_code.data(), sizeof(char), color_code.size(), target_file_);
diff --git a/include/spdlog/sinks/wincolor_sink.h b/include/spdlog/sinks/wincolor_sink.h
index 2ee3efd7..3c248192 100644
--- a/include/spdlog/sinks/wincolor_sink.h
+++ b/include/spdlog/sinks/wincolor_sink.h
@@ -41,7 +41,7 @@ public:
         : out_handle_(OutHandle::handle())
         , mutex_(ConsoleMutex::mutex())
     {
-        set_color_mode(mode);
+        set_color_mode_(mode);
         colors_[level::trace] = WHITE;
         colors_[level::debug] = CYAN;
         colors_[level::info] = GREEN;
@@ -108,21 +108,28 @@ public:
     }
 
     void set_color_mode(color_mode mode)
+    {
+        std::lock_guard<mutex_t> lock(mutex_);
+        set_color_mode_(mode);
+    }
+
+private:
+    using mutex_t = typename ConsoleMutex::mutex_t;
+
+    void set_color_mode_(color_mode mode)
     {
         switch (mode)
         {
         case color_mode::always:
         case color_mode::automatic:
             should_do_colors_ = true;
-            return;
+            break
         case color_mode::never:
             should_do_colors_ = false;
-            return;
+            break
         }
     }
 
-private:
-    using mutex_t = typename ConsoleMutex::mutex_t;
     // set color and return the orig console attributes (for resetting later)
     WORD set_console_attribs(WORD attribs)
     {