History of Colony Catalyst

The Colony Catalyst is the catalyst for The Colony, an Exotic Void Grenade Launcher.

How to complete

1. Get the catalyst: it drops randomly from defeating Guardians in the Crucible (per Destiny Game Wiki). Search results say Xûr can sell it, but I did not confirm that on an opened page.
2. Insert it (0/2 on the page: the insertion step) and defeat 500 enemies with The Colony.

Rewards

The Deeper Pockets perk (increased ammo reserves), the weapon becomes masterworked, and it generates orbs on multikills and shows the defeat count.

The weapon

The Colony comes from Exotic engrams or occasionally from Xûr.