Help. My 1993 regal 3.8 has a rough idle & the engine shutters when trying to maintain a steady speed, smooth under acceleration. Noticed coil #1, 3 & 5 have yellow spark and 2,4 & 6 have blue spark, changed coils & ignition module and runs the same. (New wires & plugs) Any help appreciated.

Welcome to AF.

Each coil fires twice per engine revolution in a GM waste spark DIS ignition system. If nothing changed when the coils and ICM were changed, then I would suspect the ECM is bad.