According to Cor-Bon:

The #12 shot is capped with a Blue ball. It produces immediate energy
dispersal, creating abrupt stopping power. It is optimally designed for
warmer climates and lighter clothing.

The larger #6 shot is capped with a Silver ball. It will typically give an additional two inches
soft tissue penetration, controlled energy release and target accuracy
with a self-defense handgun. This load is designed for colder climates and
heavier clothing.

Caliber: 45 Auto Plus P
Bullet Wt.: 145gr
Velocity: 1350fps
Energy: 587 ft lbs
Test Barrel Length: 5.0 Inches