A live example of this tutorial is here: http://www.wpsubscribers.com/demo/category-1/post-with-custom-style-footerbar.html
Step 1: Create your footerbat as usuall, let's read this tutorial if you haven't: http://www.wpsubscribers.com/tutorials/create-your-first-footerbar-opt-in-form.html
Step 2: Modify Footerbar content like me (for example):
The differenrces are:
– I use “transparent” attribute for “Form Background Color” field, or any color as you want.
– I change the “Disable Subscribe Form” value to “Disable”.
Press “Save Changes” button and then cofigure Footer form display location as usuall 🙂