It would be awesome to have other customization options, but Firefox currently only supports size and color. If Firefox supports more customization in the future, I'd love to expand the add-on.

Currently, the customizations that Firefox offers for scrollbars is pretty limited. It only supports two styles (thin or wide). I hope that Firefox will offer more customization options in the future, but for now the add-on is limited to the few options that Firefox supports.

Thanks for the feedback! I'm always looking for ways to improve the add-on, so if you could email me at [email protected] with more information of the feature that you are looking for, I'd be happy to see what I can do.