const int redPin = 5;    
const int greenPin = 9;  
const int bluePin = 6;   

void setup() {
  
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
 
  digitalWrite(redPin, HIGH);
  digitalWrite(greenPin, HIGH);
  digitalWrite(bluePin, HIGH);
  delay(1000); 
  
  for (int brightness = 0; brightness <= 255; brightness++) {
    analogWrite(redPin, brightness);
    delay(10);
  }
 
  for (int brightness = 0; brightness <= 255; brightness++) {
    analogWrite(greenPin, brightness);
    delay(10); 
  }

  for (int brightness = 0; brightness <= 255; brightness++) {
    analogWrite(bluePin, brightness);
    delay(10); 
  }
  
  for (int brightness = 255; brightness >= 0; brightness--) {
    analogWrite(redPin, brightness);
    analogWrite(greenPin, brightness);
    analogWrite(bluePin, brightness);
    delay(10);
  }
}