First of all, you didn’t mention that you need custom CSS. Moreover, you have mentioned, “Not just front page, sitewide, please?” That’s why we thought you are looking secondary color changing option.
However, we already added the secondary color changing option in the theme and will update the theme shortly in the themeforest.
Please wait with patience for the next update of the theme. You will get notified via email when the Theme update will available.
Best Regards,
ThemeLooks Support Team