The following are known Action Replay Codes for Mega Man: Dr. Wily’s Revenge on Nintendo Game Boy / Color (GB / GBC). These codes were also known as GameShark Codes and in most cases will work on both devices.

Device Compatibility: Action Replay & GameShark

Have CU, EL, IC, FI, CA, HE, FL
01ffa1df

Have QU, BU, EN
01ffa2df