int trim = 0 ;
int val = 0 ;
 
int redPin = 9 ;
int greenPin = 11 ;
int bluePin = 10 ;
 
void setup()
{
  Serial.begin(9600) ;
  pinMode( redPin, OUTPUT ) ;
  pinMode( greenPin, OUTPUT ) ;
  pinMode( bluePin, OUTPUT ) ;
}
 
void loop()
{
  val = analogRead( trim ) ;
  Serial.println(val) ;
  if( val < 100 )
  {
    setColor( 255, 0, 0 ) ;
  }
  if( val >= 100 )
  {
    if( val < 300 )
    {
      setColor( 255, 255, 0 ) ;
    }
  }
  if( val > 300 )
  {
    setColor( 0, 255, 0 ) ;
  }
}
 
void setColor(int red, int green, int blue)
{
  analogWrite( redPin, 255 - red ) ;
  analogWrite( greenPin, 255 - green ) ;
  analogWrite( bluePin, 255 - blue ) ;  
}