I don't know if this has been mentioned earlier, but my opinion is that the plant will get the benefit of a good percentage of the light being reflected from the white sand, encouraging red coloration via increased light exposure IMO (this effect obviously depends upon the specimens genetics concerning pigmentation). The last picture shows that even if it is a little bit covered, the other leaves above ground are still going through photosynthesis, producing sugars, so even with the crown covered, other leaves will pop given time!
Great plant btw, love the colors!