diff --git a/src/log.h b/src/log.h
index 952ebadb..1427d136 100644
--- a/src/log.h
+++ b/src/log.h
@@ -118,16 +118,16 @@ public:
 		m_stream(stream)
 	{
 #if !defined(_WIN32)
-		colored = (Logger::color_mode == LOG_COLOR_ALWAYS) ||
-			(Logger::color_mode == LOG_COLOR_AUTO && isatty(fileno(stdout)));
+		is_tty = isatty(fileno(stdout));
 #else
-		colored = Logger::color_mode == LOG_COLOR_ALWAYS;
+		is_tty = false;
 #endif
 	}
 
 	void logRaw(LogLevel lev, const std::string &line)
 	{
-		bool colored_message = colored;
+		bool colored_message = (Logger::color_mode == LOG_COLOR_ALWAYS) ||
+			(Logger::color_mode == LOG_COLOR_AUTO && is_tty);
 		if (colored_message)
 			switch (lev) {
 			case LL_ERROR:
@@ -160,7 +160,7 @@ public:
 
 private:
 	std::ostream &m_stream;
-	bool colored;
+	bool is_tty;
 };
 
 class FileLogOutput : public ICombinedLogOutput {
diff --git a/src/main.cpp b/src/main.cpp
index 26ad978c..e4e47b1a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -407,14 +407,25 @@ static void setup_log_params(const Settings &cmd_args)
 	}
 
 	// Coloured log messages (see log.h)
+	std::string color_mode;
 	if (cmd_args.exists("color")) {
-		std::string mode = cmd_args.get("color");
-		if (mode == "auto")
+		color_mode = cmd_args.get("color");
+#if !defined(_WIN32)
+	} else {
+		char *color_mode_env = getenv("MT_LOGCOLOR");
+		if (color_mode_env)
+			color_mode = color_mode_env;
+#endif
+	}
+	if (color_mode != "") {
+		if (color_mode == "auto")
 			Logger::color_mode = LOG_COLOR_AUTO;
-		else if (mode == "always")
+		else if (color_mode == "always")
 			Logger::color_mode = LOG_COLOR_ALWAYS;
-		else
+		else if (color_mode == "never")
 			Logger::color_mode = LOG_COLOR_NEVER;
+		else
+			errorstream << "Invalid color mode: " << color_mode << std::endl;
 	}
 
 	// If trace is enabled, enable logging of certain things