NES: Why strange colors on the sides of the screens?

[ManFranceGermany]

Since I got the NES 1988 Im asking myself, why some Titels (Mega Man series and Kirby's Adventure for example) have this Color "pixalation" at the End of the scrolling Screen?It seems like its repeating the Colors of the coming sprites/Backgrounds!? The other Question is, why some Games (like Mario Brothers 1) don't have?
Has it to do with the Palette or Modes the Game use or is it a error in the PPU?

Thanks

 

[Rydian]

On the very left?

At the time that area wasn't displayed on the screen (it was off the viewing range of most TVs), so they never worried about what was in that area. Some games bothered to cover it up, but many didn't. If you're using an emulator they sometimes have an option called "8-pixel clipping" you can turn on to hide that area.

 

[ManFranceGermany]

On the very left?

At the time that area wasn't displayed on the screen (it was off the viewing range of most TVs), so they never worried about what was in that area. Some games bothered to cover it up, but many didn't. If you're using an emulator they sometimes have an option called "8-pixel clipping" you can turn on to hide that area.

well..I mean this
(begins at 0:18)
in this example its like you said the left screen. But I don't think it was out of the range of most TVs, was it?

 

[Rydian]

It was out of range of most TVs at the time (old CRT TVs always had stuff cut off around the edges).

Current TVs that can detect the picture and format it to fit correctly will show stuff that didn't show up previously.

 

[dilav]

hmm, thats interesting. never played my nes on non CRT before. But I just got to say, Ol' school Kirby game looks fun. It may be the chiptune, but idk.. makes me want to play some kirby now.

 

[ManFranceGermany]

It was out of range of most TVs at the time (old CRT TVs always had stuff cut off around the edges).

Current TVs that can detect the picture and format it to fit correctly will show stuff that didn't show up previously.

well, probably its about PAL, but in Europe I saw this on all TVs (yap, also in the 80es and 90es)