int redpin = 11; //select the  pin for the red LED
int bluepin =10; // select the pin for the  blue  LED
int  greenpin =9;// select the pin for the green LED
 
int val;
 
void  setup() {
   pinMode(redpin, OUTPUT);
   pinMode(bluepin, OUTPUT);
  pinMode(greenpin, OUTPUT);
   Serial.begin(9600);
}
 
void  loop()
{
for(val=255;  val>0; val--)
  {
    analogWrite(11, val);
    analogWrite(10, 255-val);
    analogWrite(9, 128-val);
   delay(1);
  }
for(val=0;  val<255; val++)
  {
    analogWrite(11, val);
    analogWrite(10, 255-val);
    analogWrite(9, 128-val);
    delay(1);
  }
 Serial.println(val,  DEC);