diff --git a/include/spdlog/sinks/ansicolor_sink-inl.h b/include/spdlog/sinks/ansicolor_sink-inl.h
index bbc44d05..34bee0b0 100644
--- a/include/spdlog/sinks/ansicolor_sink-inl.h
+++ b/include/spdlog/sinks/ansicolor_sink-inl.h
@@ -34,7 +34,7 @@ template<typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color(log_level color_level, string_view_t color)
 {
     std::lock_guard<mutex_t> lock(mutex_);
-    colors_.at(static_cast<size_t>(color_level)) = to_string_(color);
+    colors_.at(to_size_t(color_level)) = to_string_(color);
 }
 
 template<typename ConsoleMutex>
diff --git a/include/spdlog/sinks/ansicolor_sink.h b/include/spdlog/sinks/ansicolor_sink.h
index 75d4f38a..d05f12ee 100644
--- a/include/spdlog/sinks/ansicolor_sink.h
+++ b/include/spdlog/sinks/ansicolor_sink.h
@@ -45,39 +45,39 @@ public:
     void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) override;
 
     // Formatting codes
-    const string_view_t reset = "\033[m";
-    const string_view_t bold = "\033[1m";
-    const string_view_t dark = "\033[2m";
-    const string_view_t underline = "\033[4m";
-    const string_view_t blink = "\033[5m";
-    const string_view_t reverse = "\033[7m";
-    const string_view_t concealed = "\033[8m";
-    const string_view_t clear_line = "\033[K";
+    static constexpr string_view_t reset = "\033[m";
+    static constexpr string_view_t bold = "\033[1m";
+    static constexpr string_view_t dark = "\033[2m";
+    static constexpr string_view_t underline = "\033[4m";
+    static constexpr string_view_t blink = "\033[5m";
+    static constexpr string_view_t reverse = "\033[7m";
+    static constexpr string_view_t concealed = "\033[8m";
+    static constexpr string_view_t clear_line = "\033[K";
 
     // Foreground colors
-    const string_view_t black = "\033[30m";
-    const string_view_t red = "\033[31m";
-    const string_view_t green = "\033[32m";
-    const string_view_t yellow = "\033[33m";
-    const string_view_t blue = "\033[34m";
-    const string_view_t magenta = "\033[35m";
-    const string_view_t cyan = "\033[36m";
-    const string_view_t white = "\033[37m";
+    static constexpr string_view_t black = "\033[30m";
+    static constexpr string_view_t red = "\033[31m";
+    static constexpr string_view_t green = "\033[32m";
+    static constexpr string_view_t yellow = "\033[33m";
+    static constexpr string_view_t blue = "\033[34m";
+    static constexpr string_view_t magenta = "\033[35m";
+    static constexpr string_view_t cyan = "\033[36m";
+    static constexpr string_view_t white = "\033[37m";
 
     /// Background colors
-    const string_view_t on_black = "\033[40m";
-    const string_view_t on_red = "\033[41m";
-    const string_view_t on_green = "\033[42m";
-    const string_view_t on_yellow = "\033[43m";
-    const string_view_t on_blue = "\033[44m";
-    const string_view_t on_magenta = "\033[45m";
-    const string_view_t on_cyan = "\033[46m";
-    const string_view_t on_white = "\033[47m";
+    static constexpr string_view_t on_black = "\033[40m";
+    static constexpr string_view_t on_red = "\033[41m";
+    static constexpr string_view_t on_green = "\033[42m";
+    static constexpr string_view_t on_yellow = "\033[43m";
+    static constexpr string_view_t on_blue = "\033[44m";
+    static constexpr string_view_t on_magenta = "\033[45m";
+    static constexpr string_view_t on_cyan = "\033[46m";
+    static constexpr string_view_t on_white = "\033[47m";
 
     /// Bold colors
-    const string_view_t yellow_bold = "\033[33m\033[1m";
-    const string_view_t red_bold = "\033[31m\033[1m";
-    const string_view_t bold_on_red = "\033[1m\033[41m";
+    static constexpr string_view_t yellow_bold = "\033[33m\033[1m";
+    static constexpr string_view_t red_bold = "\033[31m\033[1m";
+    static constexpr string_view_t bold_on_red = "\033[1m\033[41m";
 
 private:
     FILE *target_file_;