:even, :oddの使い方

A0
A1
A2
A3
A4
A5

$("tr:even").css("background-color", "red");
$("tr:odd").css("background-color", "yellow"); 

<table border="1">
  <tr><td>A0</td></tr>
  <tr><td>A1</td></tr>
  <tr><td>A2</td></tr>
  <tr><td>A3</td></tr>
  <tr><td>A4</td></tr>
  <tr><td>A5</td></tr>    
</table>