IF the CSS of a layout updated as we changed the attributes, and IF we had access/permission to do so...
I'd see this as the solution to that problem. The images we use for a layout, should be CSS driven (a code calling a resource). The code exists where we call it on the layout, the resource exists once and can be exchanged for another with the same size same type same name, etc.
Client wants 3% more red in their elements? CSS, of course.
-- sent from my iPhone4 --
Looslely related to this, I thought every design element we see in FileMaker (including it's functionality) should be available to the developer (or Advanced developer), to place on layouts as the developer sees fit. E.g. All the icons in the toolbar should be available to put on layouts, kind of the like Custom Menus for functional layout objects.