colour sensor

#include <LiquidCrystal.h>

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

#define S0 4
#define S1 5
#define S2 6
#define S3 7
#define sensorOut 8

int red,green= 0;

void setup() {
  
  //Setting up LED
  lcd.begin(16, 2);

  pinMode(S0, OUTPUT);
  pinMode(S1, OUTPUT);
  pinMode(S2, OUTPUT);
  pinMode(S3, OUTPUT);
  pinMode(sensorOut, INPUT);
  
  // Setting frequency-scaling to 20%
  digitalWrite(S0,HIGH);
  digitalWrite(S1,LOW);
  
  Serial.begin(9600);
}
void loop() {
  
  // Setting red filtered photodiodes to be read
  digitalWrite(S2,LOW);
  digitalWrite(S3,LOW);
  red= pulseIn(sensorOut, LOW);
  delay(100);

  // Setting Green filtered photodiodes to be read
  digitalWrite(S2,HIGH);
  digitalWrite(S3,HIGH);
  green = pulseIn(sensorOut, LOW);
  delay(100);
  
  //adjust the values accordingly
  if (red > 12 && red < 30   &&  grn > 40 && grn < 70    &&  blu > 33 && blu < 70)
  {   color = "RED";
      lcd.print("Stop");
      //enter function to stop the bot
  }
  
  else if (red > 50 && red < 95   &&  grn > 35 && grn < 70    &&  blu > 45 && blu < 85)  
  { color = "GREEN";
    lcd.print("GO");
    //enter function to move the bot
  }
  

}