Adding MailChimp Subscription Form

Hi, I tried installing the mailchimp form on my site at AbundantIdeas.com. The form is supposed to have a blue background and a red submit button but it is showing a white background and gray submit button. I was using the classic form option and pasted the code into my WordPress site in the right hand column of my site. Also, I was wondering if there is a way to add a custom submit button.

Thanks,

Suzanna