int i;
void setup() {
  // put your setup code here, to run once:
pinMode(8,OUTPUT);//red
pinMode(7,OUTPUT);//blue
pinMode(6,OUTPUT);//green
}

void loop() {
  // put your main code here, to run repeatedly:
  int r = 1;
    digitalWrite(8,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(6,HIGH);
    
    for  (i=255;i>0; i--){
    analogWrite(8,i);
    delay(10);
    }
    for  (i=0;i<255; i++){
    analogWrite(8,i);
    delay(10);
    }

    for  (i=255;i>0; i--){
    analogWrite(7,i);
    delay(10);
    }
    for  (i=0;i<255; i++){
    analogWrite(7,i);
    delay(10);
    }

    for  (i=255;i>0; i--){
    analogWrite(6,i);
    delay(10);
    }
    for  (i=0;i<255; i++){
    analogWrite(6,i);
    delay(10);
    }
}