For those of us who suffer from photophobia, the current stark white of Evernote makes it very painful on the eyes. At night, it can be like driving and having someone's brights hit you right in the eyes = instant headache (I have to drive with sunglasses at night, to give you an idea). This makes Evernote potentionally unusable for millions who suffer from various levels of light sensitivity and other eye coditions. I, personally, am constantly squinting my eyes when I use Evernote because it's just too bright. Yet, I still try and use it because it's a great program. It's very frustrating.
On my home computer, I have done everything I can to reduce stark whites and other similar colors/color combos that are way too bright or hurt my eyes. My windows theme is custom to a dark gray, my Word default template is set to automatically color the page a dark gray with light gray text, firefox has a dark theme applied, and I have several addons that allow me to customize the look of webpages - No color, Stylish, Greasmonkey, and Turn off the lights. Any thing I can modify, I have because I - like everyone else - don't want to suffer from eye pain and headaches if I can avoid it (plus, I just like customized things ). Evernote, unfortunately, cannot currently be changed. I sincerely hope that this changes in the future because I do love the program and find it very useful - I just can't get much use out of it currently.
Edit: I am always willing to help anyone with customizing if I can, so send me a message with any questions