#include <FastLED.h>

#define LED_PIN     3
#define NUM_LEDS    11

CRGB leds[NUM_LEDS];

int CustArray[5] = {1,3,4,6,10};


void setup() {

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

void loop() {

for(int i =0; i<5;i++){
  leds[CustArray[i]] = CRGB::Red;}
  FastLED.show();
  delay(50);

  for(int i =0; i<5;i++){
  leds[CustArray[i]] = CRGB::Black;}
  FastLED.show();
  delay(50);


}