To differentiate table rows from each other, a different shade is used as background color for every second row. Keep the difference between the two colors to a minimum to preserve a gentle feeling. The colors should be similar in value and low in saturation – the one should be slightly darker or lighter than the other. It is often seen that one of the two colors is the background color of the page itself.
The purpose of the shading in every second row is only to provide an aid for the every to follow a row from the left to the right and back again – without confusing one row with another. The purpose is not to drastically change the design of the table.
A side effect of shading every second row with an alternating color is however that the table will stand out from the rest of the page. The shading in this way boxes in the table.