Need to add sixth cell in a Grid Row

I successfully used the six-columns code for a Color Section:
#six-columns .column-top-margin { margin-top: 0px !important; }
#six-columns div .av_one_fifth { width: 15%!important; margin-left: 2%; }
#six-columns .first { margin-left: 0!important; clear: none; }
#six-columns .el_after_av_one_fifth { margin-left: 2%!important; }

I want to add a sixth cell to a grid row. Is there similar code to achieve a sixth cell in a Grid Row?