Use the treemap chart when you want to compare segments to a total and you have categories in a hierarchy. The treemap chart is best for categories with few hierarchy levels, use the sunburst chart if you have many hierarchy levels.
The treemap chart graphs data as rectangles and the color represents the category, the rectangles allows you to compare the values since the proportions are relative to each other and the whole.
The chart above shows the largest cities in Africa and Asia, cities in Asia are colored orange and blue for Africa. The largest rectangle is Tokyo and it corresponds to the population in Tokyo.
How to build
Go to tab "Insert" on the ribbon.
Click the "Insert hierarchy chart" button.
Click the "Treemap" button.
How to change the color of a category
I want to change the color of all rectangles in category CC, see picture above. To change the category color follow these steps.
Click on a rectangle that belongs to category CC repeatedly until all rectangles in category CC are selected.
The other rectangles are now faded.
Go to tab "Home" on the ribbon.
Click the "Fill color" button and pick a color.
The rectangles in category CC have now changed color.