FastLED and Neopixel Help
Never used neoPixels in arduino before so this is a complete guess based on reading the code but it looks like you are only setting the colour of the first LED.

Try creating 16 LED colours:

CRGB led[16];


and then setting them all:

for (int i = 0;i&lt;15; i++) {
  int colourIndex = index + i;
  if (colourIndex &gt; 15)
    colourIndex -= 15;
  led[i] = ColorFromPalette(auroraPalette, colourIndex , 255, LINEARBLEND);
}


edit - as @rDg indicates in his answer

FastLED.addLeds&lt;NEOPIXEL, 6&gt;(&amp;led, 16);


becomes

FastLED.addLeds&lt;NEOPIXEL, 6&gt;(led, 16);


since led is now an array not a single value

Finally I think paletteSize should only be 16 not 5*16, you only have 16 colours in there.