Adobe InDesign is a powerful software program that lets you integrate text and images into a multi-page document, such as a magazine or book layout. By default, InDesign will use CMYK colour (Cyan Magenta Yellow black) which allows for many more shades of colour than RGB (Red Green Blue). However, if you create an RGB colour swatch, or import an RGB image into the document, InDesign will keep the colour mode for those items, even if other items are in CMYK.
Open your document in InDesign. Click the "Selection Tool" in the Toolbox if it is not already selected.
Click the "Window" menu and make sure there is a check mark beside "Color." If there is not, click "Color" and the Color Panel will open.
Look at the Color panel. The attributes will tell you if the colour is in CMYK, such as "C=100 Y=90 M=10 K=0," for example. If the attributes look something like this: "R=57 G=46 B=122," then the document is in RGB, not CMYK.
Place only CMYK images into the document, and use only CMYK colour swatches when working on the document to keep it in CMYK mode. For images or colours already placed into the document, follow the instructions in the following Section to verify that each one is in CMYK mode.
Click the "Selection Tool" in the Toolbox if it is not already selected. Click on the "Window" menu, then click "Swatches" if there is not a check mark beside it.
Look at the list of swatches in the Swatches panel. Double-click any colour that is not in CMYK.
Select "Process" in the "Color Type" menu. Select "CMYK" in the "Color Mode" menu. Click "OK."
Click on every text box or shape that you have made in the document. Look at the Swatches panel. If the swatch is not in CMYK, repeat Step 3.
Click on every image you have "placed" in the document from an external source. Look at the Color panel. If it is not in CMYK format, right-click the image. Click "Graphics," then "Edit Original." The image will open in your default graphics software. Change the image to CMYK and save the image. The new settings will be applied to the image in InDesign.