Content in InDesign can have a color stroke (border) and a color fill.

Clicking the fill color or stroke color in the Properties panel reveals colors saved in a document, called swatches.

Click the fill color in the Properties panel and select the Swatches option at the top of the panel. You can then select a default color swatch from the list of swatches that appears.

Click the fill color in the Properties panel and select the Color option at the top of the panel. You can then mix a custom color. Choose CMYK from the panel menu, if necessary, to see the CMYK sliders. Click in the color spectrum to choose a color, and then adjust the color values using the CMYK sliders.

Cyan, Magenta, Yellow, and Black (K) are the colors represented by CMYK. These are printing inks that are mixed to create the final color on a printer.

To sample formatting and apply that formatting to other content, click and hold the Color Theme tool in the toolbox to select the Eyedropper tool. The Eyedropper tool captures formatting from an object you click and applies that same formatting to the selected content.