int ledR=14;
int ledY=27;
int ledG=26;

void setup()
{
  pinMode(ledG, OUTPUT);
  pinMode(ledY, OUTPUT);
  pinMode(ledR, OUTPUT);

 digitalWrite(ledG, HIGH);
 digitalWrite(ledY, HIGH);
 digitalWrite(ledR, HIGH);
}



void loop() {
  for (int i = 0; i < 255; i++) { 
    analogWrite(ledG, i);
    analogWrite(ledY,i);
    analogWrite(ledR,i);
    delay(2);
  }
  for (int i = 255; i > 0; i--) {
    analogWrite(ledG,i);
    analogWrite(ledY,i);
    analogWrite(ledR,i);
    delay(2);
  }
}