note 611 added to gtk.gtkcolorselectiondialog.php

Actually, the object breakdown shown below is not really needed.  There is a valid, but undocumented property called 'colorsel' that represents the GtkColorSelection object.  You can use it as follows:

(Borrowing the same callback)

function showme($obj) {

//Get the GtkColorSelection Object//
$colorWheel = $obj->colorsel;
print_r($colorWheel->get_color());

}

You can also use it to set the color display on the dialog, if you already have a color array (rgb) on file:

function setme($obj,$red,$green,$blue)  {

//Set the GtkColorSelection//
$colorWheel = $obj->colorsel;
$colorWheel->set_color($red,$green,$blue);

}

 http://gtk.php.net:80/manual/en/gtk.gtkcolorselectiondialog.php