Double Dukes - S4-E2
Continuity mistake: If you look closely during the first scene where Turk and Moody (disguised as Bo and Luke) reveal to Roscoe that they aren't Bo and Luke, as they peel off their faces. First Moody (as Luke) is wearing a solid light-blue shirt. When we get a close-up of his face, he is wearing Luke's traditional blue-pladed shirt, and after their masks are totally off, Moody is wearing the solid light-blue shirt again.
Answer: Various reasons, but mainly to drive the Dukes out of Hazzard County because the family have been foiling his schemes since his and Uncle Jesse's bootlegging days.
Captain Defenestrator