No RGB images
This check reports when the colour space used in any placed images is set to RGB.
Pixel images that have been captured by a digital camera or a scanner will always start off as RGB images (Red, Green, Blue). Vector drawn images can also be set to use the RGB colour mode.
If an RGB image is to be used in commercial printing it is typically converted to the ink colours CMYK (Cyan, Magenta, Yellow and Black) when outputting.
The actual colour that any RGB or CMYK describes depends on many variables such as the type and setup of screen when viewing RGB images and the ink, paper and light source used when viewing CMYK images.
Unless you are working in a colour managed workflow the movement between RGB and CMYK can cause unexpected and disappointing results and one way around this is to insist that all images are converted to CMYK in the same way before they reach the InDesign page.
Fix this problem by using a CMYK version of the same images or using an alternative image.
Tip: It is possible to switch on a Colour Space column in the Links Panel. (InDesign Window menu > Links). First choose Panel Options from the Links panel menu.
In the Panel Options dialog under the Show Column heading click the checkbox for Colour Space and click OK.
In the Links panel a new column appears indicating the Colour Space of pixel images. You may need to adjust the widths of the columns or panel itself to see all the information.
