The most important feature is that each line begins with a different color than the line above or below. As Matthew Schneps, director of the Laboratory for Visual Learning at the Harvard-Smithsonian Center for Astrophysics, explained it to me, the color gradients also pull our eyes long from one character to the next—and then from the end of one line to the beginning of the next, minimizing any chance of skipping lines or making anything less than an optimally efficient word-to-word or line-to-line transition.
