int redLED = 13;
int orangeLED = 12;
int yellowLED = 11;
int greenLED = 10;
int blueLED = 9;
int purpleLED = 8;

void setup() {
pinMode(redLED, OUTPUT);
pinMode(orangeLED, OUTPUT);
pinMode(yellowLED, OUTPUT);
pinMode(greenLED, OUTPUT);
pinMode(blueLED, OUTPUT);
pinMode(purpleLED, OUTPUT);
}

void loop() {
digitalWrite(redLED, HIGH);
delay(100);

digitalWrite(redLED, LOW);
digitalWrite(orangeLED, HIGH);
delay(100);

digitalWrite(orangeLED, LOW);
digitalWrite(yellowLED, HIGH);
delay(100);

digitalWrite(yellowLED, LOW);
digitalWrite(greenLED, HIGH);
delay(100);

digitalWrite(greenLED, LOW);
digitalWrite(blueLED, HIGH);
delay(100);

digitalWrite(blueLED, LOW);
digitalWrite(purpleLED, HIGH);
delay(100);

digitalWrite(purpleLED, LOW);
}