What you would do is create a standard subroutine that reads all WIDGET records, looking for widgets of X type (like button). When it finds a widget of that type, it could set the font, text, rollover colors, etc.

Then, call this subr in Pre-Display of any process you want to have the consistent look and feel.

One enhancement you could do is put all the attrs in a one-rec param file, so that you can change them on the fly at run-time without having to touch the code.

This works only for setting attributes for existing GUI elements, and doesn't let you create new elements and add them to processes on the fly (for example, if you want a standard button to always appear on the bottom line of all INPUT processes).