Button Label Color

I'm trying to set the button label color using this code:

style "mybutton"
{

  fg[NORMAL] = "#ffffff"
  fg[INSENSITIVE] = "#000000"
  fg[ACTIVE] = "#000000"
  fg[SELECTED] = "#000000"
  fg[PRELIGHT] = "#000000"

  engine "pixmap"
  {
....
....
....
}

but only change de focus rectangle color... i need to change the button
text when the button is pressed because the button color changes.. any
idea?