Comment Artifact colors (Score 1) 167
That the US market had a crappier output possibility, combined with a worst Video standard (nicknamed Never The Same Color
The analog TV standard in Japan was NTSC with a different black level. This is why the Famicom and NTSC NES use the same 2C02 PPU, while PAL regions need a different 2C07 PPU.
The situation is completely different from the first home computer doing "composite synthesis" and achieving more colours on the screen than supported in the GFX hardware.
You're referring to the 7.16 MHz pixel clock of several early game consoles and home computers (Apple II, Atari 400/800, Atari 7800, IBM CGA, etc.), which was exactly twice the NTSC color burst frequency. This let the program synthesize the exact waveform going out the wire. The Genesis's pixel clock, on the other hand, was 15/8 times color burst. At that rate, patterns of thin vertical lines resulted in semi-transparent rainbow effects, which weren't quite as predictable as the but still fooled the TV into making more colors. The NES pixel clock of 3/2 color burst was coarser but had a diagonal bias, allowing games like Blaster Master to create more apparent colors than the four per 16x16 pixel area that an NES game usually has by using small dots of different colors adjacent to each other and to black.