Yes it's possible. I did it and it works.
Here what Andy told me :
Version 5.0 has quite a complex structure and many of the properties can be changed on the fly using the _m() and _mi() arrays.
The only difficult part is getting the reference number of each item or menu.
_m() is the array for menus and _mi() is the array for menu items. Each menu item is numbered from 0 to the number of menu items the menu has. Once you know the item number you can change any of the properties like this.
_mi[20][7]="red" will change the offbgcolor for menu item number 20. You may then need to execute the itemOff function to activate the change, this will be itemOff(20)
There is a full list of each of the menu item properties and the associated number at
http://milonic.com/itemproperties.php
We hope to get a much more detailed demo of this posted soon.