#include <Adafruit_NeoPixel.h>
Adafruit_NeoPixel ring (50,A0,NEO_GRB + NEO_KHZ800);
int position = 10;
int b =0;

void setup() 
{
  ring.begin();
}

void loop() 
{
  ring.clear();
  for(int i = 250; i > 0;i = i-50)
  {
    if (position == 50)
    {
      position = 0;
      b = 50;
    }
    ring.setPixelColor(position + b, i, 0, 0);
    b--;
  }
  b = 0;
  position++;
  ring.show();
  delay(100);
}