Your Amaryllis (Hippeastrum 'Apple Blossom') is very pretty. I don't know why the colors sometimes fade but I have 'Aphrodite' that seems to have reverted to almost solid white blooms.
What it originally looked like ..................... what it looked like this week:
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!