The CMYK color model defines the color space used for printing. It refers to the four inks used in most printers – cyan, magenta, yellow, and key (black). CMYK mixes the colors so that they produce the desired color information on paper. RGB color model is different and is much larger than CMYK. Although it consists of only 3 mixed colors (red, green, and blue), it is able to display a much larger color gamut. The colors themselves seem brighter and more subtle, and this is the reason why images on the screen look better than when printed out. You may often convert images of one color space into another without even thinking much of those. The issue may appear though when apart from using ImageConverter Plus, you work with Photoshop. There are several profiles available for color spaces which describe their properties. A color profile is a numerical model of a color space. Operating systems and programs need to have access to a profile that describes the meaning of the color values in order to interpret the color correctly. Proper color management requires all image files to have an embedded profile. Profiles define the most saturated colors available in a color space. Utilizing command line of ImageConverter Plus, you can specify the desired color profile and apply it on thousands of images at once. In case you need to get the result similar to the one in Photoshop, use the same color profile you use in Photoshop .