How to add product attributes groups and product attributes in PrestaShop
To add attributes and groups of attributes, log in to the admin panel of your PrestaShop store, click on the Catalog tab and then on the Attributes and Groups sub-tab.
On the new page click on the button Add attributes group to add a new group of attributes. Then on the page with the settings type the name for the group, specify whether it's a color group and click on the Save button to add the group.
To add an attribute click on the Add attribute button on the Attributes and Groups home page. On the new page that opens type the name of the attribute, and from the Group drop-down menu select the attributes group to which you want the attribute to belong. Then click on the Save button.
For screenshots and some more details check out the tutorial on adding attributes and groups of attributes in PrestaShop.