Setting a Treemap Chart’s Colors Describes how to set the colors of a treemap chart. Set the Shape of a Treemap Chart Describes how to set the shape of a treemap chart. A treemap chart displays hierarchical data in rectangles proportionally sized according to the amount of data in each category. Either right-click the chart and pick Format Chart Area or double-click. The Treemap chart is a built-in chart type in Excel 2016+. For fill and line styles and colors, effects like shadow and 3-D, or exact size and proportions, you can use the Format Chart Area sidebar. Use the variety of tools in the ribbon to customize your treemap. Downloading Treemap - Custom Visualization Select the chart and go to the Chart Design tab that displays.