This post is older than a year. Consider some information might not be accurate anymore.
IntelliJ allows you to use the Darcula theme, that is in some case better, e.g. coding on a notebook to save power. It may be the taste, that this theme is desired. If you copy and paste code from IntelliJ it will be formatted with the Darcula theme. If you want a printer friendly theme, you can set the option for copying, to use another theme like Default.