Invoices generated with Zervant cannot be modified in terms of colour, text styles (e.g. font, bold, italics), layout of different elements or borders. The invoicing template is default and importing a custom template is not enabled.
However, you can choose the fields that appear on your invoices by customising your invoicing settings. For example, Message and Footnote fields allow you to enter text freely on your invoices. If you want to learn more about this, please see our article on customising invoices.
Another way to personalize your invoices is to add your company's logo. Our article on how to add your company logo might be useful should you wish to do so.