I remember colors better than I remember names. It's a difference in how I process text, and for code where there's already 'types' of syntax, colors help differentiate between all those. It's not that I can't find the for loop, it's just that visually it becomes more distinct to me if all loops are a certain color. And class names are a certain color. And those colors tend to stand out better on a dark background than a light one. Reading light themes, or even unthemed code just feels like an additional chore that's solved pretty simply by using a dark theme.