Invisible Typing when filling in forms

Hi, I’m building a holding page for a coming-soon blog and want to be able to allow people to sign up. I’ve managed to set up a mc4wp plugin form that links to a mailchimp list (thanks very much!) but when I go to type in the fields (as if I was a new subscriber) I can’t see what I’m typing (white on white) which makes it fairly impossible to use. I’m using the free version of mc4wp but can’t believe that this is a premium feature so does anyone have any advice on what I’ve done wrong?!? Thank you very much xx