1- Actually, to know how to set the video on the background with a transparent header and changing the content color please watch this complete video: https://streamable.com/7p7m72 for a better reference.
2- Please provide me the login access to your site in the below-listed format in the private content area, so that I will check and assist you accordingly.
WP Admin URL:
WP Admin Username:
WP Admin Password:
Note: Please take the complete backup of your site first.
3- For the mobile you can change the color as per you need from the theme option like this please check the video: https://streamable.com/cd8w4t
Regards 8Themes Team.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.