One way:
~Insert a new column and number each cell in that column, 1 thru X.
~Insert a new column next to that with the formula =MOD(cell
reference,2) that references each numbered cell. This will result in 1
or 0 for each cell.
~Sort all rows on the 1/0 column. Shade either the 1 section or the 0
section.
~Sort all rows again on the numbered column 1 thru X.