Introduction
Contact Form 7 forms don’t look right in the theme.
We do not directly support this plugin as it is not authored by Obox, so your theme’s styling may not necessarily jive with Contact Form 7 or Fast Secure Contact form or many of the other contact form plugins. Our newer themes are tested exclusively with Gravity Forms, which you can also download via the plugin repository.
The Solution
If you would like to stick with Contact Form 7 but want to style the forms, you will need to build some custom css for the default form, or follow the plugin’s instructions for how to build custom form fields in the form builder. Designer Eric J Hansel provides a nice walkthrough here:
http://www.ejhansel.com/style-the-contact-form-7-wordpress-plugin/