#include <Adafruit_NeoPixel.h> 
int PIN =12;
int N_LEDS =40;
Adafruit_NeoPixel ring = Adafruit_NeoPixel(N_LEDS, PIN);

void setup() 
{
  ring.begin();
}

void loop()
 {
  for(int i=0; i<N_LEDS; i++ ) 
  {
    ring.setPixelColor(i , ring.Color(0, 0, 0)); // Draw new pixel
    ring.show();
    delay(100);
    
      if (i<10)
      {
        ring.setPixelColor(i , ring.Color(0, 255, 0)); // Draw new pixel
        ring.show();
        delay(100);
      }
      else if (i>=10 and i<20)
      {
        ring.setPixelColor(i , ring.Color(255, 255, 255)); // Draw new pixel
        ring.show();
        delay(100);
      }
      else if (i>=20 and i<30)
      {
        ring.setPixelColor(i , ring.Color(255, 165, 0)); // Draw new pixel
        ring.show();
        delay(100);
      }
      else 
      {
        ring.setPixelColor(i , ring.Color(255, 255, 255)); // Draw new pixel
        ring.show();
        delay(100);
      }

  }
}