Working CMYK - soft proofs the document using the current CMYK working space defined in the Color Settings dialog.
Working Cyan, Magenta, Yellow and Black Plate or Working CMY Plates - soft proofs the document using the current
CMYK working space defined in the Color Settings dialog.
Macintosh RGB and Windows RGB - soft proofs the document using the standard Mac or Windows monitor profile (i.e. Apple RGB and sRGB respectively). Both options assume that the simulated monitor will display your document without using color management.
Monitor RGB - soft proofs the document using your actual monitor profile. Again, this option assumes that the simulated monitor will display your document without using color management.
Color Blindness - creates a soft proof that reflects colors visible to a person with color blindness. The two soft proof options, Protanopia and Deuteranopia, approximate color perception for the most common forms of color blindness.