REST API integration issues with Upfront


I am having problems trying to get the text input field's background color removed. Please reference

I am using my own code that was provided by my billing software's company. It sends an HTTP GET to an endpoint on there API. As far as I can tell the form is working correctly, I am able to log in and view the portal on there server, starting at my site. The issue that I am having is customziing the front end look on my site.

Can you help me in locating the css or code or whatever I need to, to customize the text input fields and button options for that form I have live at : ? The black backround is killing me and I've spent 4 days now trying to get this one specific thing changed. Please Help! Below is the code I am pumping into upfront via the code dragable eliment :

\\\\Code Start\\\\\

<form accept-charset="UTF-8" action="" method="post"><div style="margin:0;padding:0;display:inline"></div>
<h1>Sign In</h1>
<div class="login-fields">
<p>Sign in using ticket number and last name:</p>
<div class="field">
<label for="username">Ticket Number:</label>
<input class="login password-field" id="ticket_number" name="ticket_number" placeholder="Ticket #" type="text" />
</div> <!-- /field -->
<div class="field">
<label for="password">Last Name:</label>
<input class="login username-field" id="last_name" name="last_name" placeholder="Last Name" type="text" />
</div> <!-- /password -->
</div> <!-- /login-fields -->
<div class="login-actions">
<input class="button btn btn-warning btn-large" name="commit" type="submit" value="Sign in" />
</div> <!-- .actions -->

\\\\Code End\\\\\