ok, then open directly template_css.php, find this:
Code:
div.moduletable h3 {
color:<?php echo $columnHeading; ?>;
background: -webkit-gradient(linear, 0 0, 0 bottom, from(<?php echo $modulesHeadingBgStart; ?>), to(<?php echo $modulesHeadingBgEnd; ?>));
background: -moz-linear-gradient(<?php echo $modulesHeadingBgStart; ?>, <?php echo $modulesHeadingBgEnd; ?>);
background: linear-gradient(<?php echo $modulesHeadingBgStart; ?>, <?php echo $modulesHeadingBgEnd; ?>);
-pie-background: linear-gradient(<?php echo $modulesHeadingBgStart; ?>, <?php echo $modulesHeadingBgEnd; ?>);
position:relative;
}
delete color:<?php echo $columnHeading; ?>; and insert your definition. There is no way that will not work.