Module Variations allow for the individual styling of each module within a position, without it being global. Code wise, this is achieved by adding a class into the module code which loads from the Module Class Suffix field in the Module Manager. The theme CSS adjusts accordingly.
Enter any available suffixes at Extensions → Module Manager → Module → Module Class Suffix
There are 4 types of suffix: box1-8, ribbon1-8, footer and flush.
The Ribbon style modifies the module header with an under-wrapping ribbon graphic. Therefore, this style is best placed in the sidebar or the left most module in a row so overlap can occur. The Box style adds a colored block element around the module. Both can be placed inside any white areas: Feature, MainTop/Bottom, Content-Top/Bottom, Sidebar, Bottom & Footer. These will work in the Header, Showcase & Top positions but some may not blend as well visually.
Footer adds a single, solid, grey bar behind the module header to allow for a continuous bar across an entire module row - also confined to the white module areas. Flush will disable all padding and margin to the module for a tighter fit.