Which background color to use for Android Market's no-alpha "Hi Resolution Application Icon"

Now the Android Marke开发者_高级运维t requires developers to upload a:

Hi Resolution Application Icon, 512w x 512h, 24 bit PNG or JPEG (no alpha)

Problem: my application's icon is not a square, and because alpha is forbidden I will have to fill with some color like black. Or maybe white.

Which color should I choose?

According to the mail sent to Android developers, "the Android icon design guidelines located at http://developer.android.com/guide/practices/ui_guidelines/icon_design.html apply."

So you can use a transparent background.

Later edit: Roman Nurik (Android developer advocate @ Google) said on Twitter that it's ok to use 32-bit PNG: http://twitter.com/romannurik/status/8375870980886528.