What could it be. Or better said, what could THEY be?
Easter ...
The Egg, which can be related to the color of the dial:
Rolex Eggsplorer II 16 550:
The Chocolate... And here, we have the embarass of the choice, but let's take one of the most spectacular, another Eggsplorer, the 6610... 
Have a Great Easter, Guys.
Nicolas.