Black background and larger text

It's impossible for me to use cintanotes for more than 10 minutes without getting eye strain or a headache. Looking at the white background of a note's window is like staring directly at a light bulb, and the text is so tiny it's impossible to read at a comfortable distance. On every application I use in which I must read or edit text, I have the ability to black out the background and make the text large. For example, right now I have this page in my Firefox browser zoomed in to 200%, plus I am running an add-on called Blank Your Monitor, which changes white backgrounds to black. These are very basic features for any application in which you work with text. It would be great to see them implemented into my favorite notebook application (which I have paid for).