Transparent header effect is available on GBeaver 1.0.4. You can add this transparent header effect on any post type (posts, pages or CPTs). See the procedure below to add this header effect:
Step 1: Login to Dashboard and navigate to add/edit WP Editor screen. You may, first, need to enable the WordPress custom fields option for post types like page, post or custom post type page, if it is disabled.
Step 2: Scroll down the page and go to “Custom Fields” section. Click on “Enter new” link, enter “transparent_header” in Name input box and “yes” into Value input box. Click on “Add Custom Field” button and save the meta data. (See the attached image)
Click on “Publish” or “Update” button and live the page. Checkout the page on the browser and see the transparent effect.
See the live demo here.
Note: If you are using ACF or any other plugin for custom meta fields on your site, you can also do it using that plugin. Just remember that meta key name would be “transparent_header” and meta value would be “yes”.