These colors are used in the Sales by Inventory Code and Sales by AR Code heat maps. When you select the drop-down, a window appears displaying possible theme colors. You can select any color you wish for the start and end range values. When you select a color from the drop-down, the color appears in the start/end field and the gradient range view changes. The color range selected is used for each level you can drill down to. See Viewing Sales by Product and Viewing Sales by Customer for more information.