如何相互改变<li>或<tr>颜色

i want to change the color of li or tr whatever possible after one another.

Note:- I want to call this in while loop so static class will be no solution

I want the output lke:-

<li>line1</li> //white background
<li>line2</li> //red background
<li>line3</li> //white background
<li>line4</li> //red background

or if possible in like:-

<tr>
<td>line1</td>  //white background
</tr>
<tr>
<td>line2</td>  //red background
</tr>
<tr>
<td>line3</td>  //white background
</tr>
<tr>
<td>line4</td>  //red background
</tr>

What i am trying yet is:-

<?php
$fields = CFS()->get('gallery');
foreach ($fields as $field) { <?
<table>
<tr><td><?php echo $field['slide_title']; ?></td></tr>
<tr><td><?php echo $field['upload']; ?></td></tr>
</table>
<?php }  ?>

You could achieve this by CSS :nth-of-type odd and even selector.

JSFiddle - DEMO

li:nth-of-type(odd) {
    color:red;
}
li:nth-of-type(even) {
    color:blue;
}

And for tds selector:

JSFiddle - DEMO

table tr:nth-of-type(odd) {
    color:red;
}
table tr:nth-of-type(even) {
    color:blue;
}

You could also use CSS :nth-child selector like this:

JSFiddle - DEMO

table tr:nth-child(2n+1) {
    color:red;
}
table tr:nth-child(2n) {
    color:blue;
}

NOTE: tr:nth-child(2n) - Represents the even rows of an HTML table.

and tr:nth-child(2n+1) - Represents the odd rows of an HTML table.

try this php code,

$i = 1;
$result = "";
while(ur-condition)
{
  if($i%2 == 0)
    $result .= "<li style='background-color: red'>line$i</li>";
  else
   $result .= "<li style='background-color: white'>line$i</li>";
  $i++;
}

echo $result;

HTML

<ul>
    <li>One</li>
    <li>Two</li>
    <li>Three</li>
    <li>Four</li>
    <li>Five</li>
</ul>

CSS

*{margin:0; padding:0; font-family:Arial; font-size:12px; color:#333;}
ul, li{list-style:none;}
ul{margin:10px;}
li:nth-child(odd){background-color:blue;}
li:nth-child(even){background-color:red;}
li{line-height:22px; padding:5px; color:#fff;}

Fiddle

you can use jquery which will also work in older version of ie

http://jsfiddle.net/victor_007/96d0k2zo/

$( "tr:odd , ul li:odd" ).css( "background-color", "#bbbbff" );