[Theme Horse Support Team]

Hello @jake-3565,

It’s very simple to upgrade to premium version.
Just download the Ambition Pro zip file from your account via our site and upload it to your WP site themes directory as you did for other themes and activate it.

And for Tagline font size and color just go to your admin dashboard and go to Appearance > Customize > Ambition Theme Options there you can see the option for font size as well as font color.

Thank you!