The Marks card is where you drag fields to control mark properties such as type, color, size, shape, and so on. The fields on the Marks card are listed at the bottom of the card. Each field has an icon next to it to identify the mark property it is setting. For example, the Marks card shown below has three fields: Customer Segment is on Color, Region is on Shape, and Container is on Size. Learn more about Marks Card, Mark Types, and Mark Properties.
After a field has been added to the Marks card, you can click the icon next to the field to change the property it is controlling. The Detail and Tooltip properties don't display with an icon. However, you can click the white space where the icon would display to access the menu.
Many properties can have multiple fields. For example, you can add multiple fields to Label, Detail, Tooltip, and Color. Size and Shape can only have one field at a time.
By default, dragging a new field to Color, replaces the existing fields. Hold the SHIFT key on your keyboard while dragging a new field to add it to Color without replacing the existing fields.