Arduino RGB LED with Potmeter and Mode Switching

int r = 6;              // select the output pin for the Red LED
int g = 5;              // select the output pin for the Green LED
int b = 3;              // select the output pin for the Blue LED
int potPin = 4;         // select the input pin for the potentiometer
int buttonPin = 8;      // select the input pin for the button
int buttonState = 0;    // current state of the button
int buttonCounter = 0;  // counter to prevent switching while button is pressed
int val = 0;            // variable to store the value coming from the sensor
int mode = r;           // mode for setting which colour to change, defaults to red

void setup()
{
  pinMode(r, OUTPUT);
  pinMode(g, OUTPUT);
  pinMode(b, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop()
{
  buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH && buttonCounter == 0)
  {
    buttonCounter++;
    if (mode == r)
    {
        mode = g;
    }
    else if (mode == g)
    {
        mode = b;
    }
    else //(mode == r)
    {
        mode = r;
    }
  }
  if (buttonState == LOW)
  {
    buttonCounter = 0;
  }
  val = analogRead(potPin);         // read the value of the potentiometer
  val = map(val, 0, 1023, 0, 255);  // convert analog input to 8 bits (0 to 255)
  setIntensity(mode, val);          // and throw that value to setIntensity() to set the LEDs brightness
}

void setIntensity(int colour, int colourValue)
{
  analogWrite(colour, colourValue);
}