Hi,
1) You can set same properties of default button, go to TemplateToaster -> Click on your Button -> Elements -> (OK) Button -> Background -> Normal -> Set color for normal.
2) Same for hover button, go to TrmplateToaster -> Click on your button -> Elements -> (OK) Button ->Background -> Hover -> Set color for hover.
3) Now you can set shape, go to TemplateToaster -> Click on your button ->Elements -> Border -> Normal .
4) Same for hover shape, go to TemplateToaster -> Click on your button ->Elements -> Border -> Hover