Dashboard -> Plugins -> Add New -> Search for: “Contact Form 7 Style” -> Click “Install Now”
Dashboard -> Plugins -> Contact Form 7 Style -> Click “update now”
Dashboard -> Contact Style -> CSS Editor
Dashboard -> Contact Style -> Locate the desired template -> Quick Edit -> Check the required Contact Form 7 name -> Update
Dashboard -> Contact Style -> Add New -> Complete the settings / options and Click “Publish” or scroll down and Click “Save Style” button.
Dashboard -> Contact Style -> Create or Edit and existing custom style -> Scroll down to the Custom Style Settings metabox and there you will see the Preview Area.
We have added a small presentation below, as an answer for this question.