Subscription Widget Background

You can customize the look of the form with CSS: try adding the following code to your theme stylesheet, or to your custom CSS editor under Appearance > Edit CSS in your dashboard:

#subscribe-blog-blog_subscription-2 input[type="text"] {
background: #f56734;
color: #fff;
padding: 5px !important;
}

You can now adjust the font size, color, and other styles to fit your needs.

You can do the same for the contact form:

#contact-form input[type=text] {
background: #f56734;
}

If you’re not familiar with CSS, you can have a look at this post to learn how to find the relevant CSS selectors for each element of your site:
https://dailypost.wordpress.com/2013/07/25/css-selectors/

I hope this helps.

Thanks!