Fill and stroke
The two paints of an object

The sun selected, with a radial fill and an orange stroke, and the Fill and Stroke rows of the Fill & stroke panel

The two rows

At the top of Fill & stroke there are two identical rows, Fill and Stroke:

ElementWhat it does
Switchon, the paint is there; off, it is none. Turn it back on and the previous paint returns
Swatcha click opens the color picker (color and opacity); a checkerboard shows through a transparent color
Previewfor a gradient, the gradient; for a pattern, a checkerboard
Typethe paint: solid, linear, radial, pattern, current color

Paint types

TypeWhat happens when you choose it
solida flat color; from a gradient, it takes the gradient's first color
linear / radiala two-stop gradient is created, from the current color to white, across the object's bounding box. Switching from linear to radial keeps the colors
patternthe document's most recent pattern; if there is none, the default one is created (30 × 30, four squares in terracotta tones)
current colorthe inherited color (currentColor): the one a container declares, or black

Nothing selected: the style

With an empty selection the panel does not turn off: it describes how the next shape will be created. You choose the color while looking at the drawing instead of fixing it afterward. Writing to the style is not an undo step.

Multiple objects

With several objects selected, the panel shows the one in focus and writes to all of them: coloring ten objects at once is the normal case. On the selected letters of an open text it writes only to those; on a threaded text frame that follows another, it writes to the first frame of the story.

Dragging paints

A color, gradient or pattern dragged from its panel onto a shape becomes its fill; with ⌥, its stroke. While you drag, the target shape highlights. See Dragging paints and resources.