How to change color scheme in Janela

Hi, I'm very interested in using Janela, and I would love to purchase the adfree version of this theme. However, I need to know if I can edit the color scheme of this theme.

If I can, how do I go about doing so? I'm not remarkably code-savvy, and haven't been able to find the appropriate lines in any of the css files to make the appropriate changes. (Or I may have, but I'm not confident enough in my knowledge to do so without doing any damage.)

Please, any help would be greatly appreciated!

Unfortunately, we don't provide any services, paid or unpaid, for editing themes for individual users.