Certain custom dice can turn into Super Dice. This ability is activated when players get more than one of that types of dice! Super Dice have cosmetic effects
 
How to know if your Dice are Super Dice!
Super Dice will be indicated by a small symbol in the upper left of that dice's listing in My Collections:
How do I make them "Super"?
Once you obtain multiples of a Super-Dice capable dice set, it will automatically turn into the Super" version:
 
 
Special "Super" visual changes can vary depending on the dice! (Shimmer, Particle Effects, Droplets, etc.!)
 
So that you know, Super Dice effects are purely cosmetic and do not affect the functionality of dice rolls or odds in any way.