Palettes from the machines themselves
The Game Boy's four greens, PICO-8's sixteen fixed colours, the Commodore 64's sixteen (as measured by Pepto), CGA's cyan-magenta-white and its full sixteen, plus 4-level greyscale and 1-bit. The NES-style set uses 37 colours modelled on the 2C02's palette.
Hardware limits like per-tile colour counts are not simulated — the result looks like the era, it is not a ROM-ready asset.
Tips for a convincing retro look
Lower the width to 80–128 pixels, add a little contrast and saturation, and use Bayer 4×4 for the console cross-hatch. For Game Boy, the 4-colour palette with Floyd–Steinberg gives a classic printed-photo feel.
Questions
Which palettes are included?
Game Boy, NES-style, PICO-8, Commodore 64, CGA 4-colour, CGA 16-colour, 4-level greyscale and 1-bit black and white — plus an Auto palette made from your photo.
Is the NES palette exact?
It is a 37-colour set modelled on the NES 2C02 palette. Emulators differ on exact values, so treat it as faithful in spirit rather than bit-exact.
What does Bayer dithering do?
It mixes palette colours in a fixed checker-like pattern so gradients become textures — the look of many 8-bit and 16-bit games.
Can I use the result as a profile picture?
Yes. Export the upscaled PNG at ×4 or more so it stays crisp when the app resizes it.