#include <FastLED.h>


#define NUM_LEDS  18
#define LED_PIN   2

int delay_time = 100;

CRGB leds[NUM_LEDS]; 

void setup() {
  FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(100);
}

void loop() {

  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Red;
    FastLED.show();
    delay(delay_time);
  }  
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Yellow;
    FastLED.show();
    delay(delay_time * 0.4);
    leds[i] = CRGB::Black;
    FastLED.show();
    delay(delay_time * 0.2);
  }  


}