If you go into survivel mode and eat a golden apple(or enchented gapple) then go into powdered snow with your extra yellow hearts, you will start to freeze. Your usual red hearts will turn blue with a freezing like texture, but your extra yellow hearts from the golden apple will turn red and white, not blue as you would expect. i am pretty sure this is a bug and maybe you would have slightly lighter blue on the extra hearts if this were fixed.