This may be a very rudimentary question, but in the option for Win32::GUI button, I can't find -background option. Does this mean that I can't change the background color of the button?

I had tried adding -background=> 'black' to the button option like so but it didn't work

$main->AddButton( 
        -text => "ok",
        -left   => 226,
        -top    => 65,
                -background => 'black', #doesn't work
        },
[download]

Is there any workaround for this problem? Thanks and regards :)