Sitemap Custom Colors and Styling will be unlocked with the Pro version. Sitemap Styles section is placed under Advanced tab.
Custom Colors
You can easily change your Sitemap appearance using Custom Colors for Sitemap Header, Footer and Main Sitemap Table using awesome Color Pickers:
Branding marks
Branding Marks will be hidden just after activating the Pro Version. However, you can control its appearance via Hide Branding Marks checkbox.