Yeah, you simply add the first part to the edittheme.php
Alternativley you could say:
find:
<p {$new['cellspacing']}> <br />{$ubbt_lang['CELLSPACING']}<br> <br /><input type=text size=5 name=cellspacing value={$theme['cellspacing']} class=formboxes>and add before:
<p {$new['cellspacing']}> <br /><p {$new['cellspacing']}> <br />{$ubbt_lang['MAX_GREM']}<br> <br /><input type=text size=5 name=max_graemlins value=\"{$theme['max_graemlins']}\" class=formboxes>
