#include <FastLED.h>

#define LED_PIN  7 
#define NUM_LEDS  4

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
}

void loop()  {
  leds[0]= CRGB(255,255,255);
  FastLED.show();
  delay(1000);
  leds[1]= CRGB(255,255,255);
  FastLED.show();
  delay(1000);
  leds[2]= CRGB(255,255,255);
  FastLED.show();
  delay(1000);
  leds[3]= CRGB(255,255,255);
  FastLED.show();
  delay(1000);
  
  leds[0]= CRGB(0,255,255);
  FastLED.show();
  delay(1000);
  leds[1]= CRGB(0,255,255);
  FastLED.show();
  delay(1000);
  leds[2]= CRGB(0,255,255);
  FastLED.show();
  delay(1000);
  leds[3]= CRGB(0,255,255);
  FastLED.show();
  delay(1000);
}