Just select SAVE and from dropdown choose save preset. This is really easy done in Joomla gantry framework. You will be presentet with pop up window and you need to fill out some additional information, as name of your preset
Hit save and you are done. This gives you possibility to style individual page, by assigning preset to only selected pages on your Joomla website.
Under the hood presets are saved in gantry variable $gantry_presets. f you save a custom preset, Gantry will create a file called presets.ini in your YOUR_SITE/templates/YOUR_TEMPLATE/custom/ folder. Another option is by doing some programming ( not really ) DIY. First create screenshot of your design and make thumbnail 180px by 100px. Save your thumbnail in yourtemplatename/admin/presets folder.
Make sure you have selected ( write them down ) ALL settings you require from templateOptions.xml
When you know what you want to save as preset you need to edit another file . In your gantry root template folder open file gantry.config.
In gantry.config add all required settings. It is basically array and you must keep it that way.
When you finish with filling it up, your custom preset will be available.
These orange "dots" indicate values to be overriden. Your customer now can select and change style of the website. If however you want to set up styles in your template "out of the box" , you should use templateOptions.xml file. You must edit DEFAULT values.
Thats it. Hope you have found this article helpful. Thanks for reading.