I don't think this plugin is particularly useful in the free version. It only seems to display in Blue and gives this message in customiser once you've wasted your installing it and setting up a form.
Use custom styles?
Note: you're on the free version. Your style changes will not take effect until you upgrade to pro
So from this message and the fact the colours do not change on the front end, I deduce that this plugin is not worth having unless yo choose the paid version. Even then, I didn't rate its styling at all. The Standard CF7 looks better.