diff --git a/Demo_C/Demo/LED/LED.c b/Demo_C/Demo/LED/LED.c
index 03c6017..e635da8 100644
--- a/Demo_C/Demo/LED/LED.c
+++ b/Demo_C/Demo/LED/LED.c
@@ -15,6 +15,7 @@
 #define END_LAMP_IDX    2
 #define COLOR_AMOUNT    3
 enum color_pin {RED, GREEN, BLUE};
+enum color_spectrum {pr, pg, mr, pb, mg};
 
 static unsigned long cur_time;
 static unsigned long prev_time;
@@ -23,7 +24,7 @@ short green_state;
 short red_state;
 short blue_state;
 enum color_pin pin;
-enum color_pin spectrum_state;
+enum color_spectrum spectrum_state;
 static int lamp_idx;
 static int n_loops;
 
@@ -65,9 +66,10 @@ int PrgTic
 	// }
     if(cur_time-prev_time>=wait)
 	{
+		prev_time = cur_time;
+		update_lights(p_ta_array);
 		spectrum();
 	}
-	update_lights(p_ta_array);
 	return RC;
 }
 
@@ -75,17 +77,20 @@ void spectrum()
 {
 	switch(spectrum_state)
 	{
-		case RED:
-			--blue_state;
+		case pr:
 			if(++red_state>LIGHT_MAX) {++spectrum_state;}
 			break;
-		case GREEN:
-			--red_state;
+		case pg:
 			if(++green_state>LIGHT_MAX) {++spectrum_state;}
 			break;
-		case BLUE:
-			--green_state;
-			if(++blue_state>LIGHT_MAX) {spectrum_state = 0;}
+		case mr:
+			if(--red_state<LIGHT_MIN) {++spectrum_state;}
+			break;
+		case pb:
+			if(++blue_state>LIGHT_MAX) {++spectrum_state;}
+			break;
+		case mg:
+			if(--green_state>LIGHT_MIN) {spectrum_state = 0;}
 	}
 }