Hi chilkat,
In the Canvas size dialog box, the background parameters play only for the new area, when you want to enlarge the canvas size.
If you keep the same size, nothing happens indeed.
When a task is done you can always or quite always :
- go back, step by step, with the undo function
- fade the effect you have applied, with Menu Edition / Fade
But for your question, you need use an other way :
- Ctrl + A (Select all in the active picture) : a selection line appears on the border of the picture
- Right click in the selection / Stroke and fill
For more tips, have a look on the PhotoFiltre Web site on the Tutorials page :
http://www.photofiltre.com/