Colus was opposed to Paul, to which the Emperor unleashed his Jihadi Fremen soldiers against, to bring the Lord and his world into line. Colus was surprised by the viciousness and fervency of the Fremen as they attacked, as the Fremen stormed not only Colus's villa and it's small force; but also how the Fremen burnt down the surrounding village, and families with them.
Gurney Halleck, who led the Fremen during this Battle, had to personally crack the heads of a few Fremen warriors, and shout at the top of his lungs, to get the soldiers to cease fire. When the Arrakan natives did cease their attacks, Colus would only surrender to Halleck, and only as he was promised by Gurney that the laws of the Imperium would have to be obeyed.
Later that night, however, as Halleck inspected the remains of Colus' villa, he saw that Enno, a Jihadi solider, had killed Colus, and placed his head on a spike. To restore order and discipline, Halleck personally slit Enno's throat, and placed his head on the spike. Colus head was buried with his body on Galicia.