System Settings : Customize and Brand Rev : Use a Light Theme for Rev
  
Use a Light Theme for Rev
By default, the Light Theme in Rev is Inactive. You can change this to Active and change the Rev menu bar to white as well as the video player background, buttons, and so forth.
*To use a Light Theme for Rev:
1. Navigate to Admin > System Settings > Branding.
2. Click the Active button in the Use Light Theme section.
3. Click the Save Changes button to apply the theme.