First: Third down efficiency. The thick line in the center is the NCAA average (e.g., approximately 68% of third and ones were converted last year). There is a second line that represents an individual team's third down efficiency. Where there is a gap between the lines that gap is filled in with either red or green depending on whether it is "good" or "bad". Being above the line is good for offenses--you convert more often. Being above the line is bad for defenses--you are converted upon more often. You want to see a lot of green in these graphs.
Second: Third down distance distribution. Again, the line in the center is the NCAA average and the thinner line is the individual team's. Green is just "above"; red just "below," since there's no clear distinction on good or bad based solely on what side of the line you're on.
Third: the raw numbers. The following graph shows the underlying data used to construct the first two. Each bar represents one yard line. Blue segments are failed conversions. Red segments resulted in first downs.
In plain English, green is good. Besides the offense's great 3rd conversion percentage, there is nothing to write home about. To play around with the graphs and better clarity click here.