Gtk UI Designer,

At this moment I'm working on a new application for n800. It's a mythtv-frontend using lib gmyth. Last week I received this ui specification to implement it using Gtk:



When I received this specification the first thing I thought was to create a GtkWidget and re-implement the expose function for drawing each controls with these images. But after reading how Gtkrc and Gtk engines work, I discovered a lot of useful things which can be used to create this visual in my application without workarounds.

But now I have few other questions, is it correct to create new design specifications only for my application? Won't it break all usability? My concern is the user is adapted with the current theme and styles, and I will change lots of things in my application.

Maybe the correct way is create the application using the default Gtk controls and a new Gtk theme with these design specifications if the user choses it.

What you think?