Button default colors not applied to login form

Hi
I have two pages (forms) that I have restricted access to.

I use the members plugin to allow me to do this by role – the role is “sponsored”.

When I use the plugin’s shortcode [members_login_form /] to display the login form, it displays the form well but the button initial state uses a black background, but the text should be white instead of black. I can’t for the life of me figure out how to change that one button. The hover colors are perfect!

Here’s the code snippet I used for the ACCESS DENIED message that get displayed if the “sponsored” user is not logged in.

<div style="background-color: #fff;padding: 30px 200px 30px 200px;text-align: center">
<h1>ACCESS DENIED</h1>
<h3>Sorry, but you do not have permission to view this content.</h3>
<h2>Please login to your account if you were given permission to access this page.</h2>
<div style="width: 400px;margin: 30px 200px 30px 400px;text-align: center">[members_login_form /]</div>
</div>

Thanks for any help you can provide.
Lyse