Website "Pin to Start" in Windows phone 8 tile transparency not applied

After referring "http://ift.tt/1QXNyYW", I've used the following code to set the "pin to start" tile icon for my website...

<meta name="application-name" content="blah blah blah..">
<meta name="msapplication-TileImage" content="windows_phone_icon.png">
<meta name="msapplication-TileColor" content="transparent" />

and tried pinning the icon to my phone home screen but the background is black and it hides the phone background but other application tiles seem to be in best shape with transparent background...

I also referred to the color table specified in msdn and tried using rgba()

<meta name="msapplication-TileColor" content="rgba(255,255,255,0)" />

but to no avail...

did anybody achieved this?

you could refer the screenshot

The area around my custom shortcut is black instead of transparent

Update: The image I've used has a transparent background. I've also tried removing the "msapplication-TileColor" meta tag but still I get a black background...