Yes, when choosing which scalebar you want, click on "properties" in the dialog box. Change all the things you want, click OK. Now you can click on "Save" and save your scalebar under new name. It will now be available as one of the scalebar styles. When you use it later on, you will only have to adjust its size/length but not the other options (like colours, font, ...)
Hope this helps,
Kathi