Created by: ilikeprograms
Also allows @gray-base to be modified with less#modifyVars (see Using Less in the Browser) and the vars to cascade.
The reason I did this is that as I mentioned it allows less to cascade the changes to the @gray variables if the @gray-base variable is changed. It also makes sense as all the variables have the same value, so why not extract it into a single variable.
I have done something similar in my own variables_custom.less file for my BootstrapThemeEditor project.