Dear Xara...

... I am not enamoured to the new approach to roll-over Buttons: they cannot be used for Xara sub-menu NavBars, which I try to avoid; you cannot build your own from scratch; they are hard to change.
I have to point out that the Fancy Buttons add to this amazing mess: each one is a XAR file of around 350kB. Normal Buttons rarely pass 25kB.
All you have done is add differing Brushes and Strokes to a basic button shape.

In Web Designer Premium, you cannot create new Brushes but there are over a score of installed ones.

Where are the tutorials on how to modify components such as Buttons?
Change Line Colour of a Fancy Brush might be a good start.

Acorn