Gradient
Gradients are similar to the color variables. Define as many gradients as you want and use them throughout the admin
in the Background editor. 
They are defined in Journal > Variables > Gradient.
Gradients can only be used as backgrounds and will be found throughout the admin wherever there is a background editor available. There are several 3rd party gradient generators on the web. Simply copy/paste the gradient code in the provided code box.
The recommended syntax for gradients is background-image. So if you copy a generated code that
uses only background make sure to change the properly to background-image.