The last bar presents the total of all of them, any graph should be carefully observed and read the data, not just looking at the colors.

But if this is the norm (I don't know) when I publish the finished graphic, I will remove the totals bar.
thx
Without reading the guide, I guess just using a different color for the total and setting it a bit further apart from the historical series would make the chart much easier to read at a glance.