I agree - the Masupi does look a little yellow. The foliage has good shape, indicating correct light. You might unpot and check the roots just to be sure - paphs don't seem to mind this at all, as long as you're careful with the roots. I would say to increase your nitrogen slightly, and possibly water too. It looks a bit starved. However, the mix also looks dark (possibly indicating waterlogged medium), which concerns me. Even if you're not watering frequently, if the medium has broken down, it will stay moist too long. It could just be the photo, but no harm in checking what's going on below the surface if you have any doubts.

J

Ok, The plant was repotted within the year, so I don't think that is an issue. I did, however, move it outside with Callosum, and already the mottled patches have regained some of their color. Scars, not colored, but physical, "smudges in the leaf" have started appearing. I suspect I had it too close to the light. It just couldn't handle the light and the heat for 16 hours, coupled with my underwatering.
Thanks
Bob

Thanks, Carolyn, I'll check it out.