#define GreenPWMpin 3
#define BluePWMpin 5
#define RedPWMpin 6
void setup() {

}

void loop() {
  int red = 255;
for (int green=0; green <= 255; green++) 
{ 
  analogWrite(GreenPWMpin, green); 
  delay(1); 
  } 
for (int red=255; red >= 0; red--)
{
      analogWrite(RedPWMpin, red);
      delay(1);
}
for (int blue=0; blue <= 255; blue++) { 
  analogWrite(BluePWMpin, blue); 
  delay(1); 
  } 
  for (int green=255; green >= 0; green--)
{
      analogWrite(GreenPWMpin, green);
      delay(1);
}
for (int red=0; red <= 255; red++) { 
  analogWrite(RedPWMpin, red); 
  delay(1); 
  } 
  for (int blue=255; blue >= 0; blue--)
{
      analogWrite(BluePWMpin, blue);
      delay(1);
}

}