code: function badgeColour(collection, stat, watermarks) {
        var watermarkType = stat === "overall" ? "lines" : stat;
        var low = watermarks[watermarkType][0];
        var high = watermarks[watermarkType][1];
        var mid = (high - low) / 2;
        var value = collection[stat].pct;
        if (value < low) {
          collection[stat].colour = "red";
        } else if (value < mid) {
          collection[stat].colour = "orange";
        } else if (value < high) {
          collection[stat].colour = "yellow";
        } else if (value < 100) {
          collection[stat].colour = "green";
        } else {
          collection[stat].colour = "brightgreen";
        }
      }
docs: Helper function to determine badge colour
  @param {Object} collection - a collection of statistic properties
  @param {Object} stat - a statistic from the collection to calculate the badge for
  @param {Object} watermarks - the high and low watermarks for each statistic in collection