Example of controlling rgbw neopixels from an esp8266 using espruino firmware.

esp8266-espruino-neopixel.js

var esp = require("ESP8266");

var pin = new Pin(5);
pinMode(pin, "output");

var pixels = [
//G,R,B,W
  0,0,0,0, // LED 0
  0,0,0,0, // LED 1
  0,0,0,0, // LED 2
  0,0,0,0, // LED 3
  0,0,0,0, // LED 4
  0,0,0,0, // LED 5
  0,0,0,0, // LED 6
  0,0,0,0, // LED 7
  0,0,0,0, // LED 8
  0,0,0,0, // LED 9
  0,0,0,0, // LED 10
  0,0,0,0  // LED 11
];


function hslToRgb(h, s, l){
  var r, g, b;

  if (s === 0) {
    r = g = b = l; // achromatic
  }
  else {
    var hue2rgb = function (p, q, t) {
      if (t < 0) t += 1;
      if (t > 1) t -= 1;
      if (t < 1/6) return p + (q - p) * 6 * t;
      if (t < 1/2) return q;
      if (t < 2/3) return p + (q - p) * (2/3 - t) * 6;
      return p;
    };
    var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
    var p = 2 * l - q;
    r = hue2rgb(p, q, h + 1/3);
    g = hue2rgb(p, q, h);
    b = hue2rgb(p, q, h - 1/3);
  }
  return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}

var i = 0;
var h = 0;
var w = 0;
setInterval(function () {
  i = (i + 4) % (12*4);
  h = (h + 1) % 360;
  var rgb = hslToRgb(h / 360, 1, 0.1);
  for (var j = 0; j < 7; j++) {
    var k = j * 4 + i;
    var l = 6 - j;
    pixels[(k ) % (12*4)] = rgb[1] >> l;
    pixels[(k + 1) % (12*4)] = rgb[0] >> l;
    pixels[(k + 2) % (12*4)] = rgb[2] >> l;
  }
  if ((i % 8) === 0) {
    w = w - 4;
    if (w < 0) w += 12*4;
    pixels[w + 3] = 10;
    pixels[(w + 7) % (12*4)] = 0;
  }
  
  esp.neopixelWrite(pin, pixels);
}, 100);

esp.setCPUFreq(80);  
E.on("init", function () {
  // Workaround for neopixel library assuming 80Mhz and save not preserving it
  esp.setCPUFreq(80);  
});
save();