2
I'm assuming you're using the standard Contact module....
In contactform.php
Every place you see "50" in the form replace it with a smaller number (say "35"). This doesn't effect how many characters the field holds, just how many are displayed on screen. So, for example,
$name_text = new XoopsFormText(_CT_NAME, "usersName", [d][b][color=990000]50[/color][/b][/d], 100, $name_v);
with
$name_text = new XoopsFormText(_CT_NAME, "usersName", [b][color=000099]35[/color][/b], 100, $name_v);