Animate foreground color of a Titanium object, given a starting and ending hex value and a number of steps to take between.

anim.js

function parseColor(color) {
   // from http://www.bitstorm.org/jquery/color-animation/jquery.animate-colors.js
   var match, triplet;

   // Match #aabbcc
   if (match = /#([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})/.exec(color)) {
      triplet = [parseInt(match[1], 16), parseInt(match[2], 16), parseInt(match[3], 16), 1];

      // Match #abc
   } else if (match = /#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])/.exec(color)) {
      triplet = [parseInt(match[1], 16) * 17, parseInt(match[2], 16) * 17, parseInt(match[3], 16) * 17, 1];

      // Match rgb(n, n, n)
   } else if (match = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(color)) {
      triplet = [parseInt(match[1]), parseInt(match[2]), parseInt(match[3]), 1];

   } else if (match = /rgba\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9\.]*)\s*\)/.exec(color)) {
      triplet = [parseInt(match[1], 10), parseInt(match[2], 10), parseInt(match[3], 10),parseFloat(match[4])];

   }
   return triplet;
}
// next two from http://stackoverflow.com/a/5624139/292947
function componentToHex(c) {
    var hex = c.toString(16);
    return hex.length == 1 ? "0" + hex : hex;
}

function rgbToHex(r, g, b) {
    return "#" + componentToHex(r) + componentToHex(g) + componentToHex(b);
}

var colorSteps = []

function calculateSteps(begin, end, numSteps) {
   var startRGB = parseColor(begin),
      endRGB = parseColor(end),
      diffR = Math.ceil((endRGB[0] - startRGB[0])/numSteps),
      diffG = Math.ceil((endRGB[1] - startRGB[1])/numSteps),
      diffB = Math.ceil((endRGB[2] - startRGB[2])/numSteps);
   for(var i=0;i<numSteps;i++) {
      var r = Math.abs(startRGB[0] + diffR*i),
         g = Math.abs(startRGB[1] + diffG*i),
         b = Math.abs(startRGB[2] + diffB*i);
      if(r<0) r = 0;
      if(r>255) r = 255;
      if(g<0) g = 0;
      if(g>255) g = 255;
      if(b<0) b = 0;
      if(b>255) b = 255;
      colorSteps.push([r, g, b]);
   }
   
}

function doAnimate(obj) {
   var step = 0;
   var interval = setInterval(function() {
      obj.color = rgbToHex(colorSteps[step][0], colorSteps[step][1], colorSteps[step][2]);
      Ti.API.info('new color: ' + obj.color)
      step++;
      if(step == colorSteps.length) {
         Ti.API.info('stopped')
         clearInterval(interval)
      }
   }, 50);
}

// set your starting and ending colors here
// and the number of steps between them to take
calculateSteps('#ff0000', '#0000ff', 50); 
// then call the function, passing your button object
doAnimate(yourButtonObject);

I've written a fixed version of your gist...https://gist.github.com/guiled/4407a4e7cd21025aec3f