#include <Adafruit_NeoPixel.h>

Adafruit_NeoPixel pixels(1, 18, NEO_GRB | NEO_KHZ800);

void setup() {
  pixels.begin();
  pinMode(2, OUTPUT);
}

void loop() {
  pixels.setPixelColor(0, pixels.Color(0, 150, 0));
  pixels.show();
  digitalWrite(2, HIGH);
  delay(1000);

  pixels.setPixelColor(0, pixels.Color(150, 0, 150));
  pixels.show();
  digitalWrite(2, LOW);
  delay(1000);
}