--- | Output the given line to stdout, in green. The silly camelCase
--- name is for consistency with e.g. putStrLn.
-putGreenLn :: String -> IO ()
-putGreenLn = with_color Green . putStrLn
+-- | Don't automatically append a newline.
+display_sent :: String -> IO ()
+display_sent = hPutStrColor stdout Green
+
+display_debug :: String -> IO ()
+display_debug = putStr
+
+display_info :: String -> IO ()
+display_info = hPutStrColorLn stdout Cyan
+
+display_warning :: String -> IO ()
+display_warning = hPutStrColorLn stderr Yellow
+
+display_error :: String -> IO ()
+display_error = hPutStrColorLn stderr Red