Themes for the Editor

I want to choose color themes for the Editor. We use dark backgrounds and White text in some of our courses. This means to edit, and I have to change the color to something non-white to see, then change it again back to white so it will show up in the class. I want the ability to choose a light blue or green theme for the Editor, so I can work with both black and white text without having to change the text color every time to edit.