Using Styles#add_style is the recommended way to manage cell styling.
CellStyle defines named styles that reference defined formatting records and can be used in your worksheet.
Creats a new CellStyle object
The buildinId to use when this named style is applied
Indicates that the build in style reference has been customized.
Determines if this named style should show in the list of styles when using excel
Determines if this formatting is for an outline style, and what level of the outline it is to be applied to.
The name of this cell style
Serializes the object
The formatting record id this named style utilizes