Any hardcore hacker or coder will swear by using white text on a black background, and all casual users seem to be happy with using black on white (BoW). I will explore why this is the case.
Suppose I have an alarm which works in the following way: the time you set the alarm to go off is when the device stops producing sound. So if I were to set the alarm for one hour, it would make a constant drone sound until an hours time where it became entirely silent again (until i switched it off – where upon it would begin producing sound again). Is this good design for an alarm?
I definitely think that this would work. You would notice the ‘deafening silence’ produced when the alarm activated – it would wake you up. I haven’t tested this but I’d love for someone out there to try this for me and post results in the comments.
The key about this is that its stimulating you the entire time you don’t need stimulating. Now here’s the kicker: black on white text is doing the same thing. The background, white, is stimulating the neurons in your mind – the photons trigger your retina to react. Black does no such thing – it cannot because black is the absence of any light stimuli. Of course your mind as a result of having no visual input could ultimately end up with having more neurons firing (e.g. if the colour black reminds you of some past event whereas white doesn’t) but this is a contrived counter case.
By setting white as a background, you are constantly stimulating your retina for no reason – the whole area that you aren’t interested in is being lit up, whereas the words (which you very much are interested in) are not stimulating your retina at all. It’s completely backwards.
So why haven’t GUI designers figured this out yet? For starters, books are black on white (due to the nature of ink being black, there’s no such thing as white ink (?)) and many designers are incompetent and use skeuomorphs. Since books are black on white, GUIs should be too, right?
Books cannot be read without an external light source such as a light (e.g. the sun). If there is an external light source, its almost always certain that the area of your vision outside the book is lit up too. For this to be not true, you’d have to be in space facing away from the sun while reading a book. The book would be lit up but the background wouldnt be (because the passing photons wouldnt hit anything). In this scenario you would quickly realize that the white background is uncomforatble to read on, just like using a monitor in a dark room.
I feel that a black background is always superior, but there is an argument that the background of the text should match the ambiance of the room – so in the case of being in a light room, the background should be light) but I disagree. When you can avoid stimulating your eyes for no reason, why would you choose to? It would just make your eyes ache more.