For some reason I can't get the field to be the same. I've
setup .required style to the way I wanted to appear, but if you did
not enter the right zipcode and submit the form it refreshes back to
the big grey field. Does anyone have a solution?

Here is my style type:

.required {font-family:verdana;font-size:6.5pt; border: 1px solid
#064b86; font-family: Verdana, Arial, Helvetica, sans-serif; font-
size: 10px; background: #FFFFFF !important}

Here is my input field:

<td><INPUT name="mailingzip" type="text" class="textfield"
id="mailingzip" size="30" required regexp="^\d{5}(\-?\d{4})?$"
filter="[0-9-]" msg="Please enter a valid ZIP Code"></td>