Subset Color Tab
Subsets are groups made by the grouping of entry values.
You can use this feature to define the main color(s) of your subsets. To do this, create a formula with the help of the formula editor.
If you want to use this feature, you have to select an entry or entries with the help of the Subset Group By tab.
Formula contract. The formula runs once for each subset and uses the current subset calculation context. Its Result is used as the Delphi TColor of the complete subset series. With no formula, the next automatic palette color is used. If the formula cannot be calculated, the subset is drawn in black.

button can help you to browse a reference entry, while with the help of the
button you can cancel your selection.
and
buttons.