If you are using Markdown(or any of it's flavors), and are using some type of app(Marked, Byword, etc.) to preview the HTML, you can copy the preview's text output to a Google Doc; This works because Google Docs is a WYSIWYG editor that uses HTML for formating.
Try this experiment, copy a website's text onto a google document, and you will find that it saves all of it's original formating , including the text's background