I found this thread when searching for a Dark Theme (preferably, white font on a black background) for a newly installed Windows 7 desktop Evernote app. Evernote kept prompting me to install the desktop client, everytime I visited Evernote.com in a browser. I stopped using the desktop client over a year ago, because it did not have this ability. I use Evernote from my android and ios phones which havs Inverse Color Toggle's, and from any of my desktop's browser's, which easily can invert colors. I prefer a white on black theme because I do not see well, and it helps tremendously when reading on the web and smartphone.