Diff between buttonfacecolor and backcolor

[stevec]

I do not see a difference?

[tsupartono]

You may not see any difference on iOS7 as buttons look like labels there.
If you try on iOS6 or on Android, you will see the difference.
BackgroundColor fills the whole background area of the element (which is always rectangular)
ButtonFaceColor in contrast would fill only the button shape. If the button is not rectangular (say round), the colour would only fill that round area.