Nestopia has a high ranking in those same tests. However, according to the same tests, Mesen is actually slightly ahead of puNES, with a score of 98.1% So just because an emulator has high ratings doesn't mean it is free of issues. These test ROMs used for determining accuracy in tests, unfortunately, don't test everything that matters for accurate emulation (and in some cases, test stuff that doesn't matter for emulating any games).
There is, however, seemingly no standard level of overcropping. Note the blank blue area to the left and the green garbage on the right.Several NES games need the overscan to be cropped to look proper. Version 2.2.2 is promised to have brought improvements from Bizhawk, a more accurate emulator, but it is unknown how much is fixed.Example of faulty visuals that are exposed due to crop overscan not working.
This is why NES games appear to have different colors on different TV sets.NES emulators are similarly afflicted by this issue, as they each have their own algorithms for generating the NES color palette, meaning they all have slightly to wildly varying palettes. This means the resulting color palette often varies depending on the display's decoder. It did not seem that there was standardization until the next generation of consoles.Unlike consoles like the SNES, which natively generate the image in pure RGB, the NES/Famicom normally generates and outputs an encoded NTSC video signal, which must then be decoded by the TV's built-in NTSC decoder. SMB3 requires a lot of cropping, however the same level of cropping will obscure of the letters in the status bar in Castlevania games.
Nestopia Emulator Wiki Series Of Cabinets
Nestopia gives the user the choice to use the RGB palette featured in these cabinets, though it is not usually considered to be the definitive or "real" NES palette. The colors on these cabinets tend to be very vibrant and saturated, giving games a very distinct look compared to how they would look on the real console. Emulators such as Nestopia have the ability for the user to edit the color palette to their liking.Some arcade machines based on the NES hardware, such as the PlayChoice-10 and the Versus series of cabinets, did generate a native RGB signal, however.