Style checkbox on Contact Form 7 WordPress

I was just wondering if there was a way anybody could think of to style a checkbox that is generated in the popular Contact Form 7 plugin on WordPress?

It's difficult to try and get it to work using raw code because Contact Form 7 works in tags/shortcode.

I would just like an orange background on the box which changes colour with a tick when checked, so nothing too complex (I hope).

Thanks in advance.