Shading lines can also improve readability (this is known; the rest of this comment is speculation). It's probably not enough to simply alternating between e.g. white and off-white background, unlike for tables. More likely an alternation between 3 or 4 subtly-different colors is best; maybe these can form a pattern across additional lines (e.g. 121312321). If the difference isn't subtle enough, editing will suffer whenever you break the line count, but for reference only the human eye is pretty good at aligning subtle things. Maybe even an outright paper-texture background image? (This is more often a gimmick, but it can be useful.)