Everything worked except the customizer. I figured it might be a server issue. I tracked down the problem to the PHP version. It was 5.4 so I changed it to 5.5 and the customizer works.
However, now there’s a problem with the header image. If I try to have no header image then the default (suggested one shows up). If I choose my own then it appears dim. I want the header image to be displayed at the full brightness level. Can this be done?
The issue you have reported is caused in the site due to the older PHP version in your Web Server ( i.e version 5.4 ).We might update the theme to make the theme stable even for the older PHP version, however, as the WordPress itself recommends the use of PHP version 7 or higher, it is recommended to update the server to the newer version. Please check the recommended configuration for WordPress here :
Regarding the Header image issue, the issue you have reported is not actually a issue but the built in feature for WordPress itself that sets the default header image while no header image is chosen.
For the issue regarding the “diming” of the header image, you can remove the dim effect for the image by using the following custom CSS in your Admin Dashboard > Appearance > Customize > Additional CSS :