Correcting Colors in CMYK and RGB

Although you can perform all color and tonal corrections in RGB mode and most adjustments in CMYK mode, choose a mode carefully. Avoid multiple conversions between modes, because color values are rounded and lost with each conversion. Don’t convert RGB images to CMYK mode if they are meant for on-screen display. For CMYK images that are separated and printed, do not make color corrections in RGB mode.

If you must convert your image from one mode to another, perform most of your tonal and color corrections in RGB mode. You can then use CMYK mode for fine-tuning. The advantages of working in RGB mode are:

RGB has fewer channels. As a result, your computer uses less memory.
RGB has a wider range of colors than CMYK, and more colors are likely to be preserved after adjustments.

You can soft proof colors to see an on-screen preview of how your document’s colors will look when reproduced on a particular output device. See About soft-proofing colors.

You can edit an image in RGB mode in one window and view the same image in CMYK colors in another window. Choose Window > Arrange > New Window For (Filename) to open a second window. Select the Working CMYK option for Proof Setup, then choose the Proof Color command to turn on the CMYK preview in one of the windows.