// Neopixel Inerface
#include <Adafruit_NeoPixel.h>
#define NUMPIXELS 1
#define PIN_NEOPIXEL 4
Adafruit_NeoPixel pixels (NUMPIXELS, PIN_NEOPIXEL, NEO_GRB + NEO_KHZ800);

void setup() {
Serial.begin(115200);
pixels.begin();
pixels.setBrightness(200);
Serial.println("Hello, ESP32!");
}

void loop() {
pixels.fill (0xFF0000); function(); //Red 
pixels.fill (0x00FF00); function(); //Green 
pixels.fill (0x0000FF); function(); //Blue 
pixels.fill (0x000000); function(); //white 
}

void function() {
  pixels.show();
  delay(500);
}