#define R 13
#define G 12
#define B 11

#include <LiquidCrystal_I2C.h>
#include <Wire.h>

int interval = 750;

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  pinMode(R, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(G, OUTPUT);
  lcd.init();
  lcd.backlight();
}

void loop() {
  digitalWrite(R, HIGH);
  lcd.clear();
  lcd.print("Red");
  delay(interval);
  digitalWrite(R, LOW);
  digitalWrite(G, HIGH);
  lcd.clear();
  lcd.print("Green");
  delay(interval);
  digitalWrite(G, LOW);
  digitalWrite(B, HIGH);
  lcd.clear();
  lcd.print("Blue");
  delay(interval);
  digitalWrite(B, LOW);
}