Adobe stopped showing Gray ICCs in Photoshop and Lightroom many years ago. RGB ones are equivalent.
But standard soft-proofing in this context really doesn't show much useful info. In fact its really just the color tone -- i.e. heavy
sepia would be noticeable. (another reason for RGBs ICCs). But the color control is all in the driver so you will have
had to do all your blending sliders first and then make the ICC. So there's nothing you could do editing in LR or PS at this point.
Roy
