The settings in the Color Settings dialog box represent the “fallback” position for performing color conversions. But two commands on the Mode submenu (under the Image menu) offer much more flexibility for applying profiles and performing conversions on an image-by-image basis. In fact, Bruce hardly ever converts colors (like from RGB to CMYK) using plain ol' Mode changes, because he likes to be able to preview and select the rendering intent that does the best job on the image at hand.
Assign Profile lets you tag an image with a specified profile, or untag an image by removing its profile. It doesn't do any conversions; it simply attaches a description (an interpretation, as it were) to the numbers in the image, or removes one (see Figure 5-32).