function to control an rgb led

hello,

I've just make corrections suggested. It's working. But the colors jumps from color to another one. How can I make a fading animation between colors ?

// variables to set
var wifiSSID = "xxxx";
var wifiPass = "xxxx";

// do not touch after this line
var LED1 = D5;
var LED2 = D14;
var LED3 = D12;
var button = D4;
var colFrom = [0,0,0];
var colTo = [0,0,0];
var colFade = 0;
var powerState = "off";
pinMode(button, 'input_pulldown');

function setLeds() {
  colFade += 0.5;
  if (colFade>=1) {
    colFade = 0;
    colFrom = colTo;
    var c = E.HSBtoRGB(Math.random(),1,1);
    colTo = [ (c&0xFF)/256, ((c>>8)&0xFF)/256, ((c>>16)&0xFF)/256 ];
  }

  analogWrite(LED1,colFrom[0]*(1-colFade) + colTo[0]*colFade, {soft:true});
  analogWrite(LED2,colFrom[1]*(1-colFade) + colTo[1]*colFade, {soft:true});
  analogWrite(LED3,colFrom[2]*(1-colFade) + colTo[2]*colFade, {soft:true});
}

function power(state) {
  if (state === "on") {
    powerState = "on";
    setInterval(setLeds, 500);
  }
  if (state === "off") {
    powerState = "off";
    clearInterval();
    analogWrite(LED1, false);
    analogWrite(LED2, false);
    analogWrite(LED3, false);
  }
}

function startServer() {
  setWatch(function(){
    if (powerState === "off") {
      power("on");
      powerState = "on";
    } else {
      if (powerState === "on") {
        power("off");
        powerState = "off";
      }
    }
  }, button, {repeat:true, edge:"rising", debounce:50});
}

function onInit() {
  var wifi = require('Wifi');
  wifi.stopAP();
  wifi.connect(wifiSSID, {password:wifiPass}, function(err, data){
    if (err) {
      print('Error while connecting to access point' + wifiSSID);
      return;
    }

    print("connected? err=", err, "info=", wifi.getIP());
    startServer();
  });
}
power('off');