RGB turning red green blue then purple

/*
*Divya Inaganti
*June 14, 2017
*different RGB colors
*/
const int photoPin = A0;
const int PinRed= 9;
const int PinGreen=10;
const int PinBlue= 11;
int photoValue= 0;
int lightVal= 0;
const int pinButton = 4;
int newButton = 0;
int lastButton = 0;
unsigned long timeVal;
int minimum= 1000;
int maximum= -1000;
void setup()

{
  Serial.begin (9600);
 pinMode(photoPin, INPUT);
  pinMode (PinRed, OUTPUT);
  pinMode (PinGreen, OUTPUT);
  pinMode (PinBlue, OUTPUT);
  pinMode(pinButton, INPUT);


analogWrite(PinRed, 255);
analogWrite(PinGreen, 0);
analogWrite(PinBlue,0);
delay(200);
analogWrite(PinRed, 0);
analogWrite(PinGreen, 255);
analogWrite(PinBlue,0);
delay(200);
analogWrite(PinRed, 0);
analogWrite(PinGreen, 0);
analogWrite(PinBlue,255);
delay(200);
analogWrite(PinRed, 0);
analogWrite(PinGreen, 0);
analogWrite(PinBlue,0);

}
 void calibrate()
{
  analogWrite(PinGreen, HIGH);
 timeVal = millis();
 while(millis()- timeVal < 5000)
{
  photoValue = analogRead(photoPin);
  if(photoValue > maximum)
  {
    maximum = photoValue;
  }
  else if(photoValue < minimum)
  {
    minimum = photoValue;
  }
 }
  Serial.println(minimum);
  Serial.println(maximum);
    analogWrite(PinGreen, LOW);
}
 boolean debounce(boolean last)
 {

  boolean current = digitalRead(pinButton);
  if (last != current)
  {
    delay(5);
    current = digitalRead(pinButton);
  }
  return current;
}
void loop()
{
  newButton = debounce (lastButton);
  if (newButton == HIGH && lastButton == LOW)
  {
    calibrate();
  }
  lastButton = newButton;
  photoValue= analogRead (photoPin);
  lightVal= map(photoValue, minimum, maximum, 255, 0);
  lightVal= constrain(lightVal, 0, 255);
  analogWrite(PinBlue, lightVal);
  analogWrite(PinRed, lightVal);