2
-> Open the theme file you are trying to edit
-> If the <td> tag has a class i.e.:
<td class="classname">
....just open the style sheet(s) for the theme you are using (style.css, styleNN.css, styleMac.css) and add the following code to the section that defines the cell class class between the two squigly brackets {...} i.e.:
td.classname {
[color=FF0000]background : url(index_06.gif) no-repeat fixed center center;[/color]
)
-> If there is no class defined for the cell, create one by adding class="pickaname" to the <td> tag, then add the appropriate code to your style sheets.