visual composer and read more button style

Hi all,
I cannot find where “read more” button style is set.
I have Visual Composer and Mobilz theme installed, I’ve been looking for these settings in all wp backend, into file system and database, but I still cannot find where these buttons are styled.
They’ve got these classes on them “vc_btn3-style-flat vc_btn3-color-juicy-pink vc_btn3-shape-rounded” that I want to change. I suppose they came from visual composer, but, again, I can’t find those properties in plugin settings.
I can override them via Javascript, but I’d prefer to make a clean set up.
Thanks,
Marco