RonW is correct - what you are trying will not work. You would be better setting the class in Perl: 
my $rows;
my $class = 'odd';
for my $name ( qw(Odd1 Even1 Odd2 Even2) ) {    
    my $hash = {
        name => $name,
        class => 'row_color_'.$class,
    };
    push(@$rows,$hash);
    $class = ( $class eq 'even' ? 'odd' : 'even');
}
$template->param(DATA => $rows);

[download]
Then in your template: 
<TMPL_LOOP NAME=DATA>
<tr>
<td class="<TMPL_VAR NAME="class">"> Row <TMPL_VAR NAME="name"></td>
</tr>
</TMPL_LOOP>

[download]
Output: 
<tr>
<td class="row_color_odd"> Row Odd1</td>
</tr>
<tr>
<td class="row_color_even"> Row Even1</td>
</tr>
<tr>
<td class="row_color_odd"> Row Odd2</td>
</tr>
<tr>
<td class="row_color_even"> Row Even2</td>
</tr>

[download]

In reply to Re^3: HTML::Template __even__ by tangent
in thread HTML::Template __even__ by Anonymous Monk

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