Does Anyone Notice This While Playing Nes Games on the Wii Virtual Console?

I downloaded kirby's adventure nes from the wii shop channel and when playing the game, I noticed a vertiical blue line at the far left of the screen..it also happens when I play super mario bros 3…has anyone else come across this issue or is that supposed to be there??

Suggestion:

I have never seen it on my system while playing any of the virtual console games. I have done a little research and I believe that it is not normal.