This tweak controls whether the menu bars are transparent (translucent) or opaque.
Start a new Terminal session (in Finder click Applications > Utilities > Terminal).
To enable this setting, type (or copy and paste) the following command:
defaults write NSGlobalDomain AppleEnableMenuBarTransparency -boolean true
To reset this setting to the default value, type (or copy and paste) the following command:
defaults delete NSGlobalDomain AppleEnableMenuBarTransparency
To activate this tweak please reboot the system.
Close the Terminal session by typing exit at the prompt.
Disclaimer: Making any changes to your system can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from these modifications can be resolved. Please follow the instructions carefully and use the information provided at your own risk.