-#define low(time) ao_led_for(AO_LED_GREEN, time)
-#define mid(time) ao_led_for(AO_LED_RED, time)
-#define high(time) ao_led_for(AO_LED_GREEN|AO_LED_RED, time)
+#ifndef AO_LED_LOW
+#define AO_LED_LOW AO_LED_GREEN
+#endif
+#ifndef AO_LED_MID
+#define AO_LED_MID AO_LED_RED
+#endif
+
+#define low(time) ao_led_for(AO_LED_LOW, time)
+#define mid(time) ao_led_for(AO_LED_MID, time)
+#define high(time) ao_led_for(AO_LED_MID|AO_LED_LOW, time)