I'm new to extensions. I have created one, and it works perfectly well. But the flash UI doesn't look like the other Illustrator extensions I have. Is there a way to programmatically get the style sheet other standard extensions are using and apply that to my extension? Or is there a default style sheet for each application that I can use?
There is no standard style sheet for extensions. Generally speaking, it is good if the style of the exension is consistent with the style of the product. If the extension you are developing is CSXS extensions( controlled by Service Manager ), you can get some style info( background color, ... ) from CSXS interface. Or, if the style of the product is not dynamic changed, you can hardcode the style in your extensions.