As of Looker 3.42, we have added an option to show totals on stacked column, bar, and area charts. In order to display totals, enable the Totals Labels option the Values section of the visualization menu.
Changing the totals label color
You can change the color of the totals value labels with the Totals Color option. Clicking on the color box will open up the color wheel picker, so you can pick any color you'd like.
Hiding series and showing the totals of hidden series
If you hide some of the series, the totals will automatically display the total for only the visible series:
In order to show the totals for all the series, even if some are hidden, enable the Show Silhouette of Disable Series option. This will show totals for only the enabled series, as well as totals for all series. The disable series will appear greyed out in the visualization:
Changing the density of the totals values
The density of the total labels depends on the value density settings. Lowering the value density will lower the frequency of the totals labels: