int led1RedPin =25;
int led1GreenPin =26;
int led1BluePin =27;

int led2RedPin =14;
int led2GreenPin =12;
int led2BluePin =13;

int led3RedPin =4;
int led3GreenPin =16;
int led3BluePin =17;

void setup() {
  pinMode(led1RedPin, OUTPUT);
  pinMode(led1GreenPin, OUTPUT);
  pinMode(led1BluePin, OUTPUT);

  pinMode(led2RedPin, OUTPUT);
  pinMode(led2GreenPin, OUTPUT);
  pinMode(led2BluePin, OUTPUT);

  pinMode(led3RedPin, OUTPUT);
  pinMode(led3GreenPin, OUTPUT);
  pinMode(led3BluePin, OUTPUT);
}

void fadeRGB(int redPin, int greenPin, int bluePin, int delayTime = 5) {
  for (int i =0; i <= 255; i++) {
    analogWrite(redPin, i);
    delay(delayTime);
  }

  for (int i =0; i <= 255; i++) {
    analogWrite(greenPin, i);
    delay(delayTime);
  }

  for (int i =0; i <= 255; i++) {
    analogWrite(bluePin, i);
    delay(delayTime);
  }

  for (int i = 255; i >= 0; i--) {
    analogWrite(redPin, i);
    delay(delayTime);
  }

  for (int i = 255; i >= 0; i--) {
    analogWrite(greenPin, i);
    delay(delayTime);
  }

  for (int i = 255; i >= 0; i--) {
    analogWrite(bluePin, i);
    delay(delayTime);
  }
}

void loop() {
  fadeRGB(led1RedPin, led1GreenPin, led1BluePin);
  fadeRGB(led2RedPin, led2GreenPin, led2BluePin);
  fadeRGB(led3RedPin, led3GreenPin, led3BluePin);
}