Make set_color public in wincolor_sink to retain configurability

include/spdlog/sinks/wincolor_sink.h

@@ -50,6 +50,13 @@ public:
     wincolor_sink(const wincolor_sink& other) = delete;
     wincolor_sink& operator=(const wincolor_sink& other) = delete;
 
+    // change the  color for the given level
+    void set_color(level::level_enum level, WORD color)
+    {
+        std::lock_guard<Mutex> lock(base_sink<Mutex>::_mutex);
+        colors_[level] = color;
+    }
+
 protected:
     virtual void _sink_it(const details::log_msg& msg) override
     {
@@ -64,13 +71,6 @@ protected:
         // windows console always flushed?
     }
 
-    // change the  color for the given level
-    void set_color(level::level_enum level, WORD color)
-    {
-        std::lock_guard<Mutex> lock(base_sink<Mutex>::_mutex);
-        colors_[level] = color;
-    }
-
 private:
     HANDLE out_handle_;
     std::unordered_map<level::level_enum, WORD, level::level_hasher> colors_;